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1
Priest, Andrew. "Waste minimisation for bromination chemistry." Thesis, University of York, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325651.
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Ferguson, Douglas. "Selectivity of aryl and benzylic bromination." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340755.
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Gunbas, Duygu Deniz. "Functionalization Of Saturated Hydrocarbons: High Temperature Bromination." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12607307/index.pdf.
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ABSTRACT
FUNCTIONALIZATION OF SATURATED HYDROCARBONS:
HIGH TEMPERATURE BROMINATION
GünbaS, Duygu Deniz M.S., Department of Chemistry Supervisor: Prof. Dr. Metin Balci June 2006, 174 pages Although saturated hydrocarbons are readily available and extremely cheap starting materials, they can not be used in synthetic chemistry without prior activation. Efficient functionalization of alkanes leading to the production of useful organic chemicals in an industrial scale is of considerable interest for the chemical and pharmaceutical industries and remains a long-term challenge for chemists. In this respect, halogenations of hydrocarbons which leads to a variety of useful synthetic intermediates is an open avenue which deserves special attention. It is also noteworthy to mention that efficient methods for selective functionalization of saturated bicyclic hydrocarbons still remains elusive, albeit a number of methods employing various reagents have been developed for the C&
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H bond activation of open chain and monocyclic alkanes. Herein, we will investigate the high temperature bromination reactions as a method for functionalization of saturated bicyclic hydrocarbons such as octahydropentalene (1), octahydro-1H-indene (2) and 1a,2,7,7a-tetrahydro-1H-cyclopropa[b]naphthalene (3). The scope and the limitations of the reaction will reveal the regio-and stereoselectivity. Furthermore, formation mechanism of the products will be discussed and the chemistry of these compounds will be extended for further functionalization
4
He, P. "Solids as catalysts for regioselective bromination reactions." Thesis, Swansea University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637254.
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An introduction to a range of inorganic solids as heterogeneous catalysts in aromatic bromination reactions is given in Chapter 1. These solids involve silica, alumina, zeolites, clays, and heteropolyacids. Aromatic bromination over these solids is discussed. Regioselectivity towards the para-isomer of various alkylbenzenes is the main theme but the advantages and disadvantages of each brominating system are also discussed. In Chapter 2 the bromination of phenyl acetate (PA) is tested using zeolites, clays and AlCl3 as catalysts. Zeolite NaY was found to be the most efficient catalyst for the para-selective bromination of PA in the presence of dichloromethane. Use of NaY zeolite allows the bromination of PA to give almost exclusively the para-isomer in quantitative yield. Additionally, the effect of the counterions, activation temperature of the zeolite, and solvent on the reaction were also investigated. In Chapter 3 the bromination of PA via a solvent-free process has been investigated. Additives (i.e. acetate anhydride, NaHCO3 and NaOCOCH3) as HBr scavengers can markedly increase the selectivity for para-isomer. In particular, a mixture of zinc acetate and bromine is shown to be an efficient reagent for para-selective bromination. In Chapter 4 the separation of 4-bromophenyl acetate (4-BPA) is studied. 4-BPA can readily be separated in pure form from industrial distillation residues by selective sorption into ZSM-5 from a cyclohexane solution of the residues and subsequent desorption with acetone. Additionally, the effect of the zeolite parameters, solvent, and temperature on selective adsorption of 4-BPA, as well as re-generation of the used zeolite, have been investigated. In Chapter 5 transbromination of bromo-substituted phenols and phenyl acetates has been discussed using large-pore zeolites and AlCl3 as catalysts. The reactions involve intermolecular transbromination. HZSM-5 zeolite shows shape selectivity for the para-isomer.
5
Cailleau, Thaïs. "Towards the catalytic asymmetric bromination of alkenes." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/9132.
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This thesis relates our efforts towards the development of a general method for the catalytic asymmetric bromination of alkenes. Previous work within the group had reported the synthesis and the use of 2,6-di-[(4R,5R)-4,5-diphenyl-4,5-dihydro-1H-imidazol-2yl]-iodobenzene to catalyse the bromolactonisation of (±)-2-cyclopentene-1-acetic acid with some asymmetric induction observed. The reaction was initially postulated to proceed via formation of a hypervalent N-I(III)-Br bond in the catalyst, which by placing the electrophilic bromine in a chiral environment would allow for its selective delivery to the alkene substrate. Initial work aimed to acquire a better understanding of that reaction system and some mechanistic studies were undertaken. A different outcome to the one expected is reported and it was concluded that during the bromolactonisation reaction, no hypervalent iodine species was forming in situ and that instead a potential kinetic resolution via α-salt formation and diastereoselective halolactonisation mechanism was operating. These findings necessitated a redesign of the catalyst and the synthesis of various bis-amidine analogues is described. An unexpected rearrangement is also unveiled and its mechanism discussed. The new catalysts were screened in our asymmetric brominating system, using different alkene substrates, and the results are reported and discussed. Subsequent studies focused on elaborating a general method for the asymmetric dibromination of alkenes, where Br+ would be delivered by a stoichiometric chiral promoter. Screening of various alkene substrates to identify a suitable candidate is reported and discussed. The asymmetric dibromination of the chosen alkene is described and further investigations in order to elucidate the reasons for the lack of enantioselectivity observed are reported. Finally, attempts to synthesise Ts-DPEN following a similar route as previously developed within the group for the synthesis of DPEN is reported as a side chapter. Various attempts at the final benzoyl cleavage are described and discussed.
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Ozer, Melek Sermin. "Functionalization Of Saturated Bicyclic Hydrocarbons: High Temperature Bromination." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12612938/index.pdf.
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ABSTRACT
FUNCTIONALIZATION OF SATURATED BICYCLIC HYDROCARBONS:
HIGH TEMPERATURE BROMINATION
Özer, Melek Sermin M.Sc., Department of Chemistry Supervisor: Prof. Dr. Metin Balci January 2011, 139 pages Although hydrocarbons are readily available and extremely cheap starting materials, they cannot be used in synthetic chemistry without prior activation. The selective functionalization of saturated hydrocarbons under mild conditions is of both biochemical and industrial importance. Initially, saturated hydrocarbons such as octahydro-1H-indene 80, octahydro-1H-4,7-methanoindene 81 and bicyclo[4.2.0]octan-7-one 82 were synthesized as starting materials. Then high temperature bromination reactions of these saturated hydrocarbons as a method for C-H bond activation have been investigated and the synthetic application of the formed intermediates has been searched. Furthermore, the role of the alkyl substituents in tricyclic systems and the effect of carbonyl group in bicyclo[4.2.0] octan-7-one 82 have been studied and the mechanism for the formation of the products have been discussed. Finally, whole products were conscientiously purified and characterized.
7
Aborways, Marwa M. "Oxidative bromination and ring expansion in organic chemistry." Thesis, University of Huddersfield, 2016. http://eprints.hud.ac.uk/id/eprint/30280/.
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This thesis is composed of two independent research projects. The first major project discussed is electrophilic halogenation using inorganic halides in the presence of oxidant. This includes the conversion of tertiary propargyl alcohols in to α,α-dihaloketones. In addition, the oxidative bromination of a range of alkylbenzene derivatives using the inexpensive oxidant Oxone and sodium bromide is described with up to 4 C-H bonds being functionalised in this process. The second part of this thesis focuses on using silacyclobutanes in our aim to access new siliconcontaining chemical space. Silacyclobutanes are useful in organic synthesis because of their exciting reactivity based on their high Lewis acidity and ring strain. We describe our efforts at developing catalytic conditions for the Pd-mediated dimerisation of silacyclobutanes, as well as our preliminary results on the nickel-catalysed enantioselective ring expansion of benzosilacyclobutane with aldehydes. After Tamao-Fleming oxidation, this reaction produces extremely useful chiral benzylic alcohols.
8
Allott, Philip Hugh. "The thermochemistry of bromination of phenols and anilines." Thesis, Royal Holloway, University of London, 1986. http://repository.royalholloway.ac.uk/items/45ee4bfb-9be1-4500-9d03-2b883899c5cb/1/.
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A method has been developed for bromination of aromatic compounds in aqueous solution in an isoperibol calorimeter. The enthalpies of bromination of phenol to 2,4,6-tribromophenol and of aniline, 2-bromo-aniline, 4-bromoaniline and 2,4-dibromoaniline to 2,4,6-tribromo-aniline were measured using this method. These values were used to derive the standard enthalpies of formation of 2,4,6-tribromophenol, 2-bromoaniline, 4-bromoaniline, 2,4-dibromoaniline and 2,4,6-tribromo-aniline. The enthalpies of combustion of 2,4,6-tribromophenol and 2,4,6-tribromoaniline were measured using a rotating-bomb calorimeter. These values were used to derive the standard enthalpies of formation of 2,4,6-tribromophenol and 2,4,6-tribromoaniline. The discrepancy between these latter standard enthalpies of formation and those found using the solution calorimetric method is discussed, and possible sources of systematic error indicated. The solution calorimetric method was adapted for the thermometric titration of phenols in aqueous solution with an aqueous solution of bromine. The sequential nature of bromination of five compounds -phenol, 2-bromophenol, 2-methylphenol, 3-methylphenol and 2-hydroxy-benzoic acid - was investigated using this technique. The reasons for this sequentiality are discussed. abstract continued overleaf A complete data-processing system has been designed for the solution calorimeter. A microcomputer is used for data acquisition from the AC bridge of the calorimeter through an analogue-to-digital interface. The bridge voltage readings, once uploaded to a minicomputer, are processed to yield the corrected temperature change. Enthalpies of reaction can then be calculated and statistical analyses performed. The problems encountered in developing the system are discussed, especially with regard to the calculation of the corrected temperature change from the noisy temperature data. A least-squares cubic spline is used for curve-fitting and calculation of the first derivative of temperature versus time.
9
Dudley, Kathryn E. "An Expedited, Regiospecific para-Bromination of Activated Aryls." TopSCHOLAR®, 2017. http://digitalcommons.wku.edu/theses/1917.
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Electrophilic Aromatic Substitution (EAS) is one of the most frequently used aryl substitution methods. Aside from the fact that most EAS reactions require an acid and an oxidizer to proceed, the reactions involving activated aryls typically produce a mixture of ortho- and para- products as well as an ortho-/para- disubstituted product. Regiospecificity in aromatic substitution is key in the production of many compounds in a variety of disciplines. Since EAS is one of the most often used substitution methods, it is extremely important to develop an efficient method for regiospecific substitutions. Previous research developed a method of ortho-substitution by using hydrocarbon media, a less hazardous, greener medium, which was modified to develop a method of p-iodination (bromination), but with extensive time periods. The research presented here not only reveals an expedient, rapid method for regiospecific p-bromination, but also does so without the need for an acid or an oxidizer. The conditions for p-bromination involve the use of acetone (sometimes with cyclohexane) and NBS resulting in GC yields of p-brominated product approaching 100% in a cost and time efficient manner without the concerns of hazardous materials or byproducts like Br2 or HBr. The reaction mechanism is briefly examined as well.
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Thapa, Rajesh. "Regioselectivity in Free Radical Bromination of Unsymmetrical Dimethylated Pyridines." Miami University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=miami1263340046.
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Cansell, Gemma. "Towards a general catalytic asymmetric bromination reaction of alkenes." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414026.
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Ross, Joanne Claire. "Supported zinc bromide and its use in aromatic bromination." Thesis, University of York, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298653.
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Jalali, Elnaz. "Regiospecific P-Bromination of Activated Aromatic Systems – Greener Approach." TopSCHOLAR®, 2017. http://digitalcommons.wku.edu/theses/1950.
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The halogenated derivatives of heterocyclic compounds (haloarenes) are highly utilized in many fields of chemistry, including drug discovery, medicinal, and material chemistry. There are a variety of ways to functionalize an aromatic system and introduce halogen substituent into the ring. However, electrophilic aromatic substitution (EAS) has been the focus of growing attention, particularly for electronrich substrates.
Electrophilic aromatic bromination protocols are one of the most important electrophilic aromatic substitution reactions. However, preparation of bromoarenes classically recommends the use of highly oxidative agents along with utilizing various metal catalysts in a halogenated solvent. The corrosive and toxic nature of these reagents and need of harsh conditions for these protocols make their utility less desirable in current practice. Furthermore, lack of regioselectivity for most substituted aromatics is the other distinguished drawback, since most products contain ortho/para directors which afford a mixture of isomers.
The innovation of our procedure for the bromination of various substituted aromatic compounds is twofold in that highly regiospecific para-bromination of activated aryls by treatment with NBS has been accomplished. Although various reaction mediums, such as cyclohexane, acetone, and acetonitrile has been used in this procedure, the significant high yields of the product formation along with the very short reaction times using acetonitrile make this approach more attractive. That this regiospecific p-substitution takes place under such mild conditions leads us to question whether it is EAS.
14
Degirmenci, Volkan. "Methane Activation Via Bromination Over Sulfated Zirconia/sba-15 Catalysts." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12609021/index.pdf.
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Methane activation with bromine followed by the condensation of the methyl bromide into higher hydrocarbons or oxygenates is a novel route. However, the selective production of monobrominated methane (CH3Br) at high conversions is a crucial prerequisite. A reaction model was developed according to the kinetic data available in the literature and thoroughly studied to investigate the optimum reactor conditions for selective methane bromination in gas phase. It was concluded that at high methane (>90%) conversions dibromomethane synthesis was favored at high selectivity (~90%) under the following conditions: T=330 °
C, Br:CH4 = 3. Sulfated zirconia included SBA-15 catalysts were prepared and characterized for the catalytic methane activation via bromination. The SBA-15 sol-gel preparation technique was followed and the zirconium was added during the preparation in the form of ZrOCl2·
8H2O with 5-30 mol % ZrO2 with respect to the SiO2 content simultaneously with the silicon source (TEOS). The catalysts were sulfated in 0.25 M H2SO4 solution. The zirconium contents of the catalysts were determined by elemental analysis and 15 wt. % Zr was determined as the highest amount. XRD analysis showed the crystalline zirconia peaks only for high zirconia loadings (>
25 mol % ZrO2) indicating the good distribution of Zr in silica framework at lower loadings. BET surface areas of the sulfated catalysts are in the range of 313-246 m2/g. The porous structures of the catalysts were determined by TEM pictures, which revealed that the increase in Zr content decreased the long range order of pore structure of SBA-15 in agreement with XRD results. The acidities of the catalysts were determined by 1H MAS NMR experiments. Brø
nsted acidity was identified by a sharp 1H MAS NMR line at 10.6 ppm. The highest acidity was observed at 5.2 wt. % Zr loading according to 1H MAS NMR experiments. 29Si MAS NMR analysis showed the formation of Si-O-X linkages (X=H, Zr). Further characterization of Brø
nsted acidity was performed by FT-IR spectroscopy of adsorbed CO at 82 K. The analysis revealed that the Brø
nsted acidity of sulfated catalysts were similar to the acid strength of the conventional sulfated zirconia. In TPD experiments, the basic molecule isopropylamine (IPAm) was adsorbed and decomposition temperature of IPAm was monitored. The temperature decreased from 340 °
C to 310 °
C in sulfated catalysts, indicating the acidic character of these samples. Catalytic methane bromination reaction tests were performed in a quartz tubular reactor. The results showed that 69% methane conversion was attainable over SZr(25)SBA-15 catalyst at 340 °
C. The liquid 1H NMR measurements of the products revealed that >
99% methyl bromide selectivity was achieved.
15
Redmond, Joanna. "The development of a catalytic asymmetric bromination reaction of alkenes." Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/8835.
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This thesis describes our investigations into the development of a general method for the catalytic, asymmetric bromination of alkenes. The bromination catalysts employed in the research are ortho-substituted iodobenzenes, which are hypothesised to deliver Br+ to the alkene substrate via a hypervalent I(III)-Br bond. Initially, endeavours to achieve a large scale preparation of our asymmetric bromination catalyst, 2,6-di-[(4R,5R)-4,5-diphenyl-4,5-dihydro-1H-imidazol-2-yl]iodobenzene, or R-IBAM, are detailed. In order to facilitate this, a large quantity of enantiopure 1,2-diphenylethylene diamine was required to form the chiral amidine moieties of our R-IBAM catalyst. Thus, the development of two novel methods for the synthesis and resolution of 1,2-diphenylethylene diamine are described and the subsequent application of each route to a large scale preparation of the enantiopure diamine. The subsequent novel and optimised preparation of our catalyst to produce 25 g of R-IBAM is detailed. The following studies into the catalytic asymmetric bromination of alkenes include the screening of the various reaction conditions, stoichiometric addition of N-bromosuccinimide to the catalysts and the synthesis and screening of a range of R-IBAM derivatives and analogues. An improved understanding of the catalytic cycle and the possible mechanisms of loss of enantioexcess in our brominated product is detailed. The final section of the thesis describes research into the exchange of Br+ between enantiopure bromonium ions and alkenes. The generation of an enantiopure bromonium ion in the absence of alkene was achieved via the rearrangement of enantiopure bromohydrin, (2S)-1-bromo-1-phenylpropan-2-ol. The intermediate bromonium ion was trapped by chloride to produce the enantiopure bromochlorinated product. This, to the best of our knowledge, represents the first example of the generation and trapping of an enantiopure bromonium ion. Our subsequent investigations into Br+ transfer from the bromonium ion to added alkene are described.
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Boys, Sarah K. "Tyrosine derivatives and their anti-cancer applications." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/6243.
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The incorporation of a propargyl group to a natural product target allows for a streamlined approach to the investigation of structure activity relationships (SARs) and target identification in forward chemical genetics programmes using a ‘click’-based approach. To this end, an efficient synthesis of O-propargylated tyrosine derivatives was designed, and these have been used in the construction of peptide motifs both (a) derived from phage display libraries and (b) found in natural products. The L-tyrosine derivative Y* (compound I, X=H, R=H) was incorporated into a peptide sequence, PTTIYY, which is known to prevent the inhibition of p53 by the AG-2 protein. Y* has been included as both the terminal and the internal tyrosine in the peptide sequence. ELISA assays were carried out to determine how the binding of PTTIYY* and PTTIY*Y to AG-2 compared to that of the un-marked PTTIYY sequence. The results of these assays allowed new conclusions to be drawn regarding the important binding features of the peptide and possible sites for further optimisation of the AG-2 binding properties of this peptide through ‘click’ functionalisation of the modified tyrosine. The binding of the peptides incorporating Y* was also assessed using MCF-7 breast cancer cell lysate, known to contain the AG-2 protein. These results confirmed those seen for the purified AG-2 ELISA. The related bromo-D-tyrosine derivative (compound I, X=Br, R=Me) has been prepared and employed towards the synthesis of a bisebromoamide derivative. Bisebromoamide is a newly discovered polypeptide, and a promising anti-cancer agent. The bisebromoamide derivative contains a thiazole unit (Tzl), two N-methylated amino acids, and an oxopropyl pyrrolidine (Opp) moiety, which is unique to bisebromoamide in natural products. The activity of this bisebromoamide derivative will be investigated via ‘click’-based affinity chromatography using a new supported linker recently developed within the Hulme group.
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Hakim, Mas Rosemal. "Stereoelectronic effects in brominations of cyclopropylarenes and 9-alkylanthracenes." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54185.
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The free radical bromination of several cyclopropylarenes has been studied. The abstraction of a cyclopropyl hydrogen by bromine atom, which to date has been an unrecognized process, is demonstrated in this study. Specifically, when a cyclopropyl group is attached to the 9-position of an anthracene, an unprecedented hydrogen abstraction product, the corresponding cyclopropyl bromide, is obtained. This is believed to be due to stereoelectronic effects. Molecular mechanics calculations and X-ray crystallography have been used to demonstrate that 9-cycIopropylanthracene, unlike other cyclopropylarenes, is effectively locked in a conformation which places the a-cyclopropyl C-H bond in alignment with the p-orbitals of the aromatic system. This proper alignment activates the a-cyclopropyl hydrogen for abstraction by bromine atom. The relative reactivities of several 9-alkylanthracenes towards bromine atom are established, namely: 9-methyI- > 9-cyclopropyI- > 9-ethyl- >> 9-isopropylanthracene. Semi-empirical molecular orbital theory and molecular mechanics calculations have been utilized to demonstrate that the relative reactivities are not a function of bond dissociation energies but rather a function of the size of the dihedral angle between the a C-H bonds and the plane of the central ring of the various 9-alkylanthracenes in their lowest energy conformations. The absolute rate constants for the abstraction of hydrogen by bromine atom from 9-methyl-, 9-cyclopropyl-, and 9·ethylanthracene are estimated to be 1.1 x 10⁸ M⁻¹ sec⁻¹, 3.8 x 10⁷ M⁻¹ sec⁻¹ and 7.2 x 10⁶ M⁻¹ sec⁻¹ respectively. The value for the primary hydrogen/deuterium isotope effect for the abstraction of hydrogen by bromine atom from 9-cyclopropylanthracene is determined to be 2.6. All of the above observations lend support to the importance of stereoelectronic effects in the free radical bromination of the cyclopropylarenes and 9-alkylanthracenes.Ph. D.
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Lawrence, Ruth. "N-oxides as organocatalysts for the Baeyer-Villiger oxidation and bromination reactions." Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.723313.
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This thesis is concerned with exploring novel applications of N-oxides as organocatalysts. Specifically, aromatic N-oxides have been successfully implemented as catalysts within the Baeyer-Villiger oxidation of α,β-unsaturated ketones and electrophilic aromatic bromination reactions. Chapter 1 provides a review of the current applications of N-oxides, highlighting their use as organic oxidants, neutral ligands and in particular organocatalysts. These roles exploit several key features of the N-oxide, including the intrinsic weakness and polarity of the N→O bond, their Lewis basicity and ability to function as hydrogen bond acceptors. As organocatalysts, these species have predominantly been utilised as nucleophilic catalysts, however their potential to act as hydrogen bond catalysts represents an emerging area of interest. Chapter 2 describes the development of an organocatalysed Baeyer-Villiger oxidation, for which N-oxides and carboxylates have been identified as suitable catalysts. The optimised protocol, which employs DMAP as the pre-catalyst, was applied to a wide range of saturated and more specifically α,β-unsaturated ketones, with enhanced reaction rates and/or chemoselectivities achieved in the majority of cases. From extensive mechanistic studies, it is proposed that the N-oxide functions as a hydrogen bond acceptor; facilitating concerted proton transfer within the addition step. The unique role of the catalyst allowed for predictions to be made about the rate determining step of the oxidations performed. A series of by-products obtained from the over oxidation of (E)-4-phenyl-3-buten-2-one were characterised and the mechanistic pathway for their formation has been fully elucidated. Development of the reaction conditions for the selective formation of many of these species is also provided. Additionally, the novel reactions of 3-(4-methoxyphenyl)but-3-en-2-one are examined. Chapter 3 details investigations into the applicability of the novel, relatively bench stable formate ester, (formyloxy)(phenyl)methyl acetate, as a formylating reagent. A high yielding and operationally simple procedure for the synthesis of this formate ester from commercially available, inexpensive (E)-4-phenyl-3-buten-2-one is described in Chapter 2. A solvent and catalyst free protocol has been developed for the N-formylation of various amino species including primary and secondary (aliphatic and aromatic) amines and an amino acid ester as well as the O-formylation of alcohols. Demonstrating its synthetic utility, the developed methodology was applied to the one-pot synthesis of an isocyanide from the corresponding amine as well as the N-formylation of an unprotected amino acid under aqueous conditions. Chapter 4 outlines preliminary studies into the application of N-oxides as nucleophilic catalysts for electrophilic aromatic bromination reactions with elemental bromine. The development of novel methodology for the 4-picoline N-oxide catalysed regioselective monobromination of tert-butylbenzene is discussed, for which a reactive N-oxide bromine complex is thought to be generated in situ. Conditions have also been established for a KI promoted system, with IBr proposed as the catalytic species. Both methodologies allow for selective electrophilic aromatic bromination of toluene in the light without competitive benzylic bromination. Chapter 5 contains experimental procedures and compound characterisation data for Chapters 2-4 inclusive.
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Gumus, Selahaddin. "Secondary Electronic and Solvent Effects on Regiospecific P-Bromination of Aromatic Systems." TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/3031.
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Bromoarenes are important aromatic building blocks that are commonly used to synthesize various functional compounds in pharmaceutical, agrochemical and related industries.1,2 This great demand for bromoarenes makes their preparation a widely studied area of synthetic organic chemistry. However, further understanding of the reactivity and regiochemistry of aromatic functionalization reactions is still necessary, as much about the secondary substitution and solvent effects remain unknown.
Resonance Theory is a widely used theoretical model to predict the regiospecifity and reactivity of the bromination of various aromatic compounds.3 The reactivity and regiospecificity of many substituted aromatic compounds is well explained using resonance theory.4 However, kinetic understanding of the p-bromination of halosubstituted aromatic compounds has not been investigated to the best of our knowledge.5,6In this thesis, the reactivity and regiospecifity of the p-bromination of activated secondary substituted aromatic compounds as well as media effects on the process will be discussed.
Synthesizing bromoarenes has been accomplished using many different experimental setups.7-11 N-bromosuccinimide is the most highly utilized electrophilic aromatic brominating agent. Many of the NBS- based aromatic bromination reactions have been reported using strong acids, strong bases, halogenated solvents, nonpolar solvents and polar solvents alike.12 The bromination reactions reported herein were performed using two different solvents, acetonitrile and acetone, to investigate the effects of solvent polarity on p-bromination. Although acetonitrile is one of the most commonly used solvents in the p-bromination of aromatic compounds, acetone has not been investigated.
20
Ålander, Lovisa. "Evaluation of lipid bromination : For the relative measurement of a chlorine gas biomarker." Thesis, Umeå universitet, Kemiska institutionen, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-184523.
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McAllister, Linda. "Experimental and theoretical studies of the halogen bond and the electrophilic bromination reaction." Thesis, University of York, 2014. http://etheses.whiterose.ac.uk/6965/.
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The work presented in this thesis is an investigation into the halogen bond using both experimental and theoretical techniques. These studies have contributed toward the understanding of the interaction during a period when the definition of this interaction was being debated.1 The interactions investigated have a range of strengths; varying from the very weak interactions with rare gas atoms to the strong interactions with halonium ions acting as halogen-bond donors. The competition and cooperation between halogen and hydrogen bonds have been investigated including a situation where halogen bonding can be favoured over hydrogen bonding. Small-molecule analogues of orthogonal halogen and hydrogen bonding observed in biological systems have also been produced. The similarity between the two interactions has been highlighted by the fact that the Steiner-Limbach equation can model the bonding in both cases. New halogen-bonded liquid crystals between dihalogens and alkoxystilbazoles and alkoxyphenylpyridines have been synthesised and the complexes between elemental iodine and alkoxystilbazoles unexpectedly showed SmC phases with high stability. Attempts to synthesise equivalent liquid crystals with elemental bromine were unsuccessful, an electrophilic bromination reaction followed by elimination of HBr taking place instead. In order to understand this reaction further, the intermediates of the electrophilic bromination reaction for different substituted stilbenes was investigated computationally and the results showed that a carbocation intermediate is favoured if an electron-donating substituent is present. In contrast, stilbenes with two electron-withdrawing substituents favoured symmetric bromonium ion intermediates. Such halonium ion intermediates feature a halogen atom that carries a positive charge, which can interact with Lewis bases in a novel category of halogen bonding, which has properties similar to halogen bonding with traditional halogen-bond donors.
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Lanoix, Stéphanie. "Development of Radical Cascade via Gold(I) Photocatalysis and Application towards One-Pot Bromination/Carbocyclization." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32062.
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Radical chemistry is a crucial tool to organic chemists. Recent trends in the field have been directed towards the development of photocatalysts capable of generating a radical through a renewable source like sunlight using a single electron transfer mechanism. The use of Au2dppm2Cl2, having a stronger reducing potential, allows an expansion of the reactivity to those achieved by iridium and ruthenium catalysts.1 The focus of this thesis is axed on the development of Au2dppm2Cl2 as an efficient photoredox catalyst for a tandem one-pot catalysis and its application in a dual catalytic system.
The use of Au2dppm2Cl2 in a dual catalysis for the synthesis of β-amino acids was undertaken. The problems encountered over the course of the investigation showed an insufficient oxidation potential of the photoredox catalyst in addition to the facile homolytic cleavage of the C-halogen bond under UV light. However, this shows great promise for the achievement of beta amino acids using solely organocatalysis.
The development of a tandem one-pot radical cyclization for the synthesis of fused- carbocycles, which are frequently encountered scaffolds in diterpenoid natural products, is reported. The initial experiments were conducted on a model substrate, enabling the verification of the proposed hypothesis. The success of this methodology was then applied to various substrates affording the desired fused 5 membered rings in good yields. These reactions show tremendous potential in the field of total synthesis for the rapid access of complex molecular structures. (1) Revol, G.; McCallum, T.; Morin, M.; Gagosz, F.; Barriault, L. Angew. Chem. Int. Ed. 2013, 52, 13342.
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Stastny, Angela. "Stoichiometric Delivery of Halogens to Substrates and a Study of Selective Bromination of Olefins by a Pt(IV) Complex." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1523629125459729.
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Turner, Isabelle. "The study of ß-cyclodextrin interactions with sugars using inhibition kinetics and the bromination of pyrimidine derivatives." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0001/MQ43636.pdf.
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Smith, Maureen McBride. "Modeling trihalomethane formation in bromide-containing surface water undergoing conventional treatment." CSUSB ScholarWorks, 1993. https://scholarworks.lib.csusb.edu/etd-project/638.
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Arévalos, Villalba Cibeli May. "ESTUDO DA CINÉTICA DA REAÇÃO QUÍMICA TRADICIONAL E ELETROQUÍMICA DE TETRABROMAÇÃO DO P-XILENO E DO 2,5-DICIANO-PXILENO." Universidade Estadual de Ponta Grossa, 2018. http://tede2.uepg.br/jspui/handle/prefix/2700.
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O texto deste trabalho esta dividido em três capítulos. No Capítulo 1 tem-se a revisão bibliográfica onde é apresentada a aplicação dos compostos orgânicos bromados, a principal forma de síntese destes e as mudanças que vêm ocorrendo devido o uso de solventes prejudiciais à camada de ozônio. Serão descritos métodos alternativos de sínteses, sendo que o mais abordado é o método eletroquímico usado, portanto neste trabalho, por meio do qual é possível realizar a bromação de anéis aromáticos e bromação de aromáticos na posição benzílica. Também serão apresentadas as aplicações dos compostos sintetizados: α, α α’, α’-tetrabromo-pxileno e α, α, α’, α’-tetrabromo-2,5-diciano-p-xileno. No Capítulo 2 são apresentados os estudos experimentais e teóricos, onde se buscou uma explicação para as diferenças observadas na reação química tradicional de tetrabromação benzílica no 2,5-diciano-p-xileno em comparação ao p-xileno. Para isso se realizou para cada composto a reação de Wohl-Ziegler por 10 horas, recolhendo-se amostras em cada tempo determinado, estas amostras formam analisadas por Ressonância Magnética Nuclear de Hidrogênio (RMN de H1) e Cromatografia Gasosa acoplada a Espectrometria de Massas (CG-MS). Também foi realizado um estudo teórico de carga a partir de simulação computacional. O que se observa é que o composto contendo o substituinte nitrila apresenta uma reação de bromação mais lenta com a formação de quatro compostos intermediários, enquanto que para o composto sem substituinte a reação é mais rápida e apenas dois compostos intermediários são observados. No Capítulo 3 é descrito um método alternativo de síntese para a tetrabromação benzílica do 2,5-diciano-p-xileno e do p-xileno. A obtenção destes compostos ocorre usando-se reações eletroquímicas, onde não é necessário o uso de solventes de venda proibida (CCl4). Também se realizou um acompanhamento cinético, analisando-se as amostras coletadas por RMN de H1 e CG-MS, para fazer a comparação de síntese pelo método tradicional e eletroquímico. Sendo que a principal diferença observada é que no método eletroquímico as reações são mais lentas, também com este método é possível continuar adicionando bromos na posição benzílica ao composto p-xileno, obtendo-se este composto pentabromado e hexabromado.
The text of this paper is divided into three chapters. In Chapter 1 there is a bibliographic review where the application of brominated organic compounds is presented, the main form of synthesis of these and the changes that have been occurring due to the use of solvents harmful to the ozone layer. It will be described alternative methods of synthesis, and the most approached is the electrochemical method used, therefore in this work, through which it is possible to perform the bromination of aromatic rings and bromination of aromatics in the benzylic position. The applications of the synthesized compounds: α, α, α', α'-tetrabromo-p-xylene and α, α, α ', α'-tetrabromo-2,5-dicyano-p-xylene will also be presented. In Chapter 2 we present experimental and theoretical studies, where an explanation was sought for the differences observed in the traditional chemical reaction of benzylic tetrabromination in 2,5-dicyano-p-xylene compared to p-xylene. In order to do this, the reactions of Wohl-Ziegler were carried out for 10 hours. Samples were collected at each determined time. These samples were analyzed by Hydrogen Nuclear Magnetic Resonance (H1 NMR) and Gas Chromatography Coupled to Mass Spectrometry (CG-MS). A theoretical load study was also carried out from a computer simulation. What is observed is that the compound containing the nitrile substituent has a slower bromination reaction with the formation of four intermediate compounds, whereas for the compound without substituent the reaction is faster and only two intermediate compounds are observed. In Chapter 3 an alternative method of synthesis for the benzylic tetra-bromination of 2,5-dicyano-p-xylene and p-xylene is described. The production of these compounds occurs using electrochemical reactions, where it is not necessary to use solvents of prohibited sale (CCl4). Also, a kinetic monitoring was performed, analyzing the samples collected by H1 NMR and CG-MS, to make the comparison of synthesis by the traditional and electrochemical method. As the main difference observed is that in the electrochemical method the reactions are slower, also with this method it is possible to continue adding bromines in the benzylic position to the compound p-xylene, obtaining this compound pentabromado and hexabromado.
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Fantinel, Leonardo. "Síntese de 2-fenil-3H-pirimidin-4-onas 6-metilsubstituídas e 4- trifluormetil-2-ureído pirimidinas." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/4171.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThis study was carried out in three parts: At first, three methods for the bromination of 6-alkylsubstituted 2-phenyl-3H-pyrimidin-4-ones was developed for the synthesis of: (i) a new series of 6-alkylsubstituted 5-bromo-2-phenyl-3H-pyrimidin-4-ones, (ii) a new series of 6-(1-bromoalkyl)-2-phenyl-3H-pyrimidin-4-ones, and (iii) e new series of 5-bromo-6-(1-bromoalkyl)-2-phenyl-3H-pyrimidin-4-ones. On the second part, the brominated pyrimidines obtained, were used to synthesize new 6-methylsubstituted 2-phenyl-3Hpyrimidin-4-ones from the reaction of the brominated pyrimidinones with primary and secondary amines, pyridine and sodium azide. On the third part, a new series of 5- e 6-substituted 4-trifluoromethyl-2-ureido pyrimidines was prepared, in good yields, from the cyclocondensation reaction of β- alkoxyvinyl-trifluoromethylketones substituted and dicyanodiamide. The products synthesized in this study were obtained in good yields and were characterized by GC-MS and 1H e 13C RMN spectroscopy. The purity of the products was assured by elemental analysis. Some compounds such as 5-bromo-2-phenyl-6-propyl-3H-pyrimidin-4-one, 5-bromo-6-(1- bromopropyl)-2-phenyl-3H-pyrimidin-4-one, 5-bromo-6-(1-bromobutyl)-2-phenyl-3H-pyrimidin-4-one, 6-(1-azidoethyl)-5-bromo-2-phenyl-3H-pyrimidin-4-one, 6-(1-azidopropyl)-5-bromo-2-phenyl-3H-pyrimidin-4-one, and 6-(1-azidobutyl)-5-bromo-2-phenyl-3H-pyrimidin-4-one, exhibited significant antimicrobial activity against some microorganisms, such as Candida albicans, Saccharomyces cerevisiae, Staphylococcus aureus, Salmonela, Klebsiela pneumonie among others.
Este trabalho foi realizado em três etapas. Na primeira, foram desenvolvidos três métodos de bromação de 2-fenil-3H-pirimidin-4-onas 6-alquilsubstituídas para a obtenção de: (i) uma série inédita de 5-bromo-2-fenil-3H-pirimidin-4-onas 6-alquilsubstituídas, (ii) uma série inédita de 6-(1- bromoalquil)-2-fenil-3H-pirimidin-4-onas e (iii) uma série inédita de 5-bromo-6-(1-bromoalquil)-2-fenil-3H-pirimidin-4-onas. Na segunda etapa, as pirimidinas bromadas, obtidas na etapa anterior, foram utilizadas para sintetizar novas 2-fenil-3H-pirimidin-4-onas 6-metilsubstituídas através de reações das pirimidinonas bromadas com aminas primárias e secundárias, piridina e azida de sódio. Na terceira etapa, foi sintetizada uma nova série de 4-trifluormetil-2-ureído pirimidinas 5- e 6-substituídas a partir de reações de ciclocondensação entre -alcoxivinil-fluormetilcetonas substituídas e dicianodiamida. Os produtos sintetizados neste trabalho foram obtidos em bons rendimentos e foram caracterizados por CG-EM e RMN de 1H e 13C. A pureza dos produtos foi comprovada por análise elementar. Alguns compostos como 5-bromo-2-fenil-6-propil-3H-pirimidin-4-ona, 5-bromo-6-(1-bromopropil)-2-fenil-3H-pirimidin-4-ona, 5-bromo-6-(1-bromobutil)-2-fenil-3Hpirimidin-4-ona, 6-(1-azidoetil)-5-bromo-2-fenil-3H-pirimidin-4-ona, 6-(1- azidopropil)-5-bromo-2-fenil-3H-pirimidin-4-ona e 6-(1-azidobutil)-5-bromo-2-fenil-3H-pirimidin-4-ona, apresentaram atividade antimicrobiana significativa contra alguns microorganismos como Candida albicans, Saccharomyces cerevisiae, Staphylococcus aureus, Salmonela, Klebsiela pneumonie e outras.
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Proust, Nicolas. "Neighboring group participation of sulfonamido nitrogens observed towards the synthesis of selected bicyclic sulfamides having sulfur at the apex position. Efforts towards the total synthesis of massarilactone A." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1217531664.
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Parulekar, Sumedh. "A novel approach to manipulate cavity size In resorcinarenes." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001810.
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Gunawan, Steven. "Enabling Chemistry to Expedite the Delivery of Pharmacologically Relevant Small Molecules." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/265595.
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Operationally friendly protocols to produce libraries of novel small molecules with high molecular complexity are in huge demand for the interrogation of biological systems. As such, development of new MCRs and post-condensation modification of the MCR products have proven fruitful in the quest for new molecular probes and their expedited progression along the drug discovery value chain. The products thereof have found their way into numerous corporate compound collections. Crixivan (Indinavir), an antiretroviral, and Xylocaine (Lidocaine), a local anesthetic, are two examples of drugs derived from an MCR that have been marketed. The research topic of this dissertation encompasses the design and development of fifteen novel drug-like chemotypes in an operationally friendly, green, and expedited (≤ 3 synthetic operations) manner involving the Ugi MCR coupled with MAOS and high-throughput purification platforms. Over 500 drug-like small molecules (purity > 90% based on UV 214 nm and ELSD) have been synthesized, purified, and submitted to the NIH MLSMR for further biological evaluation against protein targets of interest. Furthermore, non-electrochemical carbamate oxidations enabling formation of N-acyliminium ion precursors, which are reactive intermediates that form the basis of a multitude of synthetic routes to natural products, have also been developed.
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Noble, Kristen Felice. "Tailored Chain Sequences of Brominated Syndiotactic Polystyrene Copolymers via Post-Polymerization Functionalization in the Heterogeneous Gel State." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/93515.
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This dissertation demonstrates the preparation of blocky brominated syndiotactic polystyrene (sPS-co-sPS-Br) copolymers with tailored chain sequences using a simple, post-polymerization functionalization method conducted in the heterogeneous gel state, and investigates the effect of sPS reaction state and sPS/solvent gel morphology on the copolymer microstructure and thermal properties. Gel-state (Blocky) brominated copolymers were prepared from a 10 w/v% sPS/carbon tetrachloride (CCl4) gel and a 10 w/v% sPS/chloroform (CHCl3) gel in a matched set containing 6−32 mol% p-bromostyrene (Br-Sty) units. For comparison, a matched set of randomly brominated copolymers was prepared using a homogeneous solution-state (Random) reaction method and a set of brominated copolymers was prepared using a heterogenous powder-state (Powder) reaction method. The degree of bromination was evaluated using 1H nuclear magnetic resonance (NMR) spectroscopy. Powder-state bromination produced copolymers with a limited degree of functionalization of up to 12 mol% Br and required a threefold longer reaction time than the gel-state method conducted on the sPS/CHCl3 gel, demonstrating that the powder-state method is time-consuming and the dense sPS powder is incapable of producing copolymers with high Br-content. Microstructural characterization provided by 13C NMR spectroscopy, showed that bromination of sPS produces multiple peaks in the quaternary carbon region of the NMR spectrum, signifying through-bond communication between neighboring styrene and Br-Sty monomers. This work provides the first high-resolution comonomer sequencing of brominated sPS copolymers. Characterization of the quaternary carbon spectrum, assisted by band selective gradient heteronuclear multiple bond correlation (bsgHMBC) spectroscopy, electronic structure calculations, and simulated statistically random copolymer chains, revealed that each resonance peak could be assigned to a styrene or Br-Sty unit that exists in the center of a unique sequence of five monomers (i.e., a pentad) along the copolymer chain (e.g., ssssb where s = styrene and b = brominated styrene). Our comonomer sequencing method demonstrated that the Blocky and Powder copolymers have block-like character. Remarkably, the Blocky copolymers exhibit notably higher degrees of blockiness and larger fractions of sssss and bbbbb pentads at low Br contents (i.e., 32 mol% Br), relative to the Powder copolymers, confirming their blocky microstructure. Quenched films of the Blocky copolymers, analyzed using ultra-small-angle (USAXS) and small-angle X ray scattering (SAXS), show micro-phase separated morphologies that are reminiscent of conventional block copolymer phase behavior, supporting that the Blocky copolymers contain distinct segments of pure sPS and segments of randomly brominated sPS. Crystallization behavior of the copolymers, examined using differential scanning calorimetry (DSC), demonstrates that the Blocky copolymers are more crystallizable and crystallize faster at lower supercooling compared to their Random analogs. Simulations of blocky copolymers were developed based on the semicrystalline gel morphology to rationalize the effect of gel-state functionalization on copolymer microstructure and crystallization behavior. The simulations confirm that restricting the accessibility of the brominating reagent to monomers well removed from the crystalline fraction of the gel network produces copolymers with a greater prevalence of long runs of pure sPS that is advantageous for preserving desired crystallizability of the resulting blocky copolymers. To investigate the effect of sPS/solvent gel morphology on copolymer microstructure and crystallization behavior, the sPS/CCl4 and sPS/CHCl3 copolymers were compared directly. Characterization of the sPS/solvent gels using USAXS/SAXS, revealed that the gels exhibit different morphologies and average lamella thicknesses. Microstructural analysis showed that the sPS/CHCl3 copolymers contain larger fractions of sssss pentad and a greater degree of blockiness. The sPS/CHCl3 copolymers contain larger phase domains, supporting that these copolymers contain longer distinct segments of pure sPS and randomly brominated sPS in a multiblock-like microstructure. In addition, the sPS/CHCl3 copolymers are more crystallizable during conditions of rapid cooling and crystallize faster at low supercooling relative to their sPS/CCl4 analogs. Simulated average chains of the Blocky copolymers, generated from the empirical pentad sequence distributions, provide strong evidence that the runs of pure sPS in the Blocky copolymers originate from the crystalline stems within the crystalline lamellae. Thus, the simulations support that semicrystalline blocky brominated copolymers with tailored chain sequences, phase behavior, and crystallization properties and can be prepared simply by changing the gelation solvent.Doctor of Philosophy
Block copolymers are a class of large molecules (polymers) that are made up of two or more chains (blocks) of different smaller units (monomers) linked together at one of each of the chain ends. When the monomers that make up each block have distinctly different chemical properties, the blocks may be capable of self-assembling into well-ordered physical structures, which give the block copolymer unique material properties that are different, and often better than the properties of the individual blocks alone (homopolymers). Block cop olymers have thus received tremendous attention with respect to controlled preparation, tailored structure development, and customized physical properties, for their potential use in self-assembled, nanostructured materials. Nevertheless, the generally difficult procedures and conditions required to make (polymerize) block copolymers with controlled sequences limits the scope of their commercial application. As an alternative to conventional polymerization methods, this dissertation demonstrates a comparatively simple physical method to make copolymers that contain significantly non-random (blocky) monomer sequences, starting with a homopolymer and using a reagent to modify units along the polymer chain. This post-polymerization method is conducted in the homopolymer’s gel state, in which segments of the homopolymer chains are effectively shielded from the reagent. The homopolymer, syndiotactic polystyrene (sPS), was used as a model to conduct a fundamentical investigation into the effects of the polymer reaction state, i.e., gel, solution, or powder, and the gel structure (morphology) on the copolymer structure and properties. The gel-state was found to produce copolymers with a high degree of modification and a greater degree of blockiness than the solution-state and powder-state. Copolymers prepared from the gel state exhibited properties that are characteristic of conventional block copolymers. Furthermore, using the gel-state method, blocky copolymers with tailored chain sequences and properties were prepared by simply changing the gel morphology. Thus, reaction in the gel-state is demonstrated as a simple physical approach to polymer design and synthesis that will be useful in the development of next-generation functionalized materials through the modification of lowcost commodity polymers. As an advancement to the manner in which nanostructured materials are created, these tailored materials will greatly enhance the convenience of block copolymers for a wide variety of applications including structural and biomechanical materials, and polymeric membranes for energy conversion and water purification systems.
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Venham, Lanny Dean. "Kinetic studies of alpha-silyl radicals : 1) relative rates of bromination of substituted benzyltrimethylsilanes : 2) laser flash photolysis study of the absolute rates of formation of alpha-silyl radicals /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487268021746361.
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Grayfer, Tatyana. "Synthèse totale de la mallotojaponine C et bromofonctionnalisations de polyprénoïdes initiées par l'iode(III) hypervalent." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS349/document.
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Le paludisme est une maladie parasitaire qui présente une problématique de santé majeure, touchant actuellement plus de 200 millions de personnes dans le monde. Le développement de nouveaux médicaments est nécessaire pour succéder aux traitements existants qui perdent progressivement leur efficacité suite à l’émergence des résistances. Les produits naturels constituent une source d’inspiration inépuisable pour la recherche de nouveaux médicaments. Dans le cadre de cette thèse, nous nous sommes intéressés à deux familles de produits à propriétés antipaludiques : les mallotojaponines et les bromophycolides. Dans la première partie du projet, nous avons effectué la première synthèse totale de la mallotojaponine C. Nous avons également synthétisé une bibliothèque de ses analogues. Tous ces composés ont été testés contre Plasmodium falciparum responsable du paludisme et contre Trypanosoma brucei responsable de la maladie du sommeil. Nous avons confirmé l’activité antipaludique des mallotojaponines et découvert leur activité trypanocide. Dans la deuxième partie de ce projet, nous avons mis au point une méthode sélective et chimiodivergente de bromation des terpènes qui pourrait ensuite être appliquée à la synthèse des bromophycolides. En utilisant des réactifs d’iode(III) hypervalent pour générer des espèces bromonium électrophiles in situ à partir des bromures, nous avons réussi à mettre au point des conditions de bromocarbocyclisation, d’oxybromation et de dibromation des chaînes terpéniques. Dans tous les cas, les réactions sont rapides et faciles à mettre en œuvreMalaria is a parasitic disease affecting more than 200 million people in the world. The development of new antimalarial drugs is necessary in order to replace the existing treatments that are progressively becoming less efficient due to resistance phenomena. Natural products are an inexhaustible source of inspiration for the discovery of new drugs. In this project, we focused our attention on two natural products families exhibiting antimalarial properties: mallotojaponins and bromophycolides. In the first part of this project, we carried out the first total synthesis of mallotoajaponin C. We also synthesised a library of its analogues. All of these compounds were tested against Plasmodium falciparum responsible for malaria and against Trypanosoma brucei responsible for African sleeping sickness. We have confirmed the antimalarial activity of mallotojaponins and discovered their trypanocidal activity. In the second part of the project, we developed a chemodivergent and selective method of bromination of terpenes that could later be applied to the synthesis of bromophycolides. Using simple bromides and hypervalent iodine(III) reagents to generate electrophilic bromonium species in situ, we have shown that the reaction can be steered selectively towards the bromocarbocyclisation, the oxybromination or the dibromination of terpene chains. In all cases, the reactions are fast and easy to perform
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Azizoglu, Akin. "Bicyclic Strained Allenes: Incorporation Of An Allene Unit Into Alpha-pinene And Benzonorbornadiene." Phd thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/12605053/index.pdf.
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The first part of study describes an investigation aimed at the incorporation of an allene unit into a natural compound, being alpha-pinene, by using Doering-Moore-Skatteboel method. DFT computations show that both allene product and insertion product can be isolated if the reaction of methyllithium with 3,3-dibromo-2,7,7-trimethyl-tricyclo[4.1.1.02,4]octane is carried out at either low or high temperatures. One insertion product resulting from the intramolecular C-H insertion at the bridge and three allene dimers were isolated when this reaction was carried out at room temperature.
In the second part of study, exo- and endo-cyclopropylidene incorporated into benzonorbornadiene were investigated by using theoretical and experimental methods. Theoretical calculations show that the endo-carbene would be stable and undergo some kind of insertion and addition reactions. On the contrary, the exo-carbene is not stable and isomerizes to the corresponding allene structure during the optimization process.
For this purpose, the reaction of dibromocarbene and dichlorocarbene with 7-methoxybenzonorbornadiene was achieved to afford gem-dibromocyclopropane and gem-dichlorocyclopropane adducts, respectively. However, they suffer stereoelectronically-controlled ring opening under the reaction conditions to give the ring-expanded allylic dihalides, respectively.
On the other hand, gem-bromofluorocyclopropane, obtained by the treatment of 7-methoxybenzonorbornadiene with bromofluorocarbene, provided one of the four possible [2+4] allene adducts upon treatment with MeLi in furan. The exact structure of the adduct has been elucidated on the basis of NMR spectral data. This result confirms the formation of the bicyclic allene as an reactive intermediate. No products were isolated derived from the endo-carbene.
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Ouchefoun, Moussa. "Nouvelles applications analytiques des ions tribromures : cas des petroles." Paris 6, 1988. http://www.theses.fr/1988PA066454.
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Elaboration d'une nouvelle technique qui associe un agent original de bromation (le tribomure de tetrabutylammonium) a un dosage voltamperometrique. Cette nouvelle technique permet non seulement de determiner un indice de brome dans le cas des fractions lourdes des petroles, mais encore pour la premiere fois d'effectuer une discremination entre reaction d'addition et reaction de substitution
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Iikawa, Shinya. "Conception d'agents antipaludiques autour du motif γ-hydroxy-γ-lactame : synthèses et évaluation biologique." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10172.
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La recherche de nouvelles molécules pour le traitement du paludisme est un domaine de recherche toujours d'actualité. L'émergence de résistance aux différents agents antipaludiques de première génération (chloroquine, quinine, mefloquine) est un grave problème dans les zones endémiques nécessitant un effort soutenu pour pouvoir proposer un nouveau traitement en combinaison avec des dérivés de l'artemisinine. Le présent projet s'inscrit dans cet effort avec comme souci de proposer une nouvelle famille de molécules simple d'accès, à faible coût et si possible avec un mécanisme d'action original. Nous nous sommes plus particulièrement intéressés à des dérivés de type γ-hydroxy-γ-lactame car ce motif n'est que très peu étudié dans la conception d'agents antiparasitaires bien que présent dans un certain nombre de molécules d'origine naturelle et il offre également la possibilité d'un certain nombre de variations structurales. La synthèse de ce type de structures utilise l'acide tétronique comme réactif de départ commercial, permettant dans un premier temps d'accéder en 3-4 étapes à des γ-lactones insaturées en série tétronique; de nombreuses modifications chimiques autour de ce motif ont été proposées à partir d'une séquence alkylation ou benzylation, aldolisation, et déshydratation. L'introduction de motifs halogénés sur ce type de structures permet ensuite d'accéder, après différents couplages catalysées au palladium (Sonogashira, Stille et Suzuki-Miyaura) à une grande diversité de composés ; également une ouverture vers des dérivés d'acides tétroniques possédant un motif 1,2,3-triazole à partir d'une réaction de cycloaddition 1,3-dipolaire catalysée au cuivre est présentée. Les différentes γ-lactones insaturées en série tétronique sont ensuite mises en réaction en présence de différentes amines afin de construire le cycle γ-hydroxy-γ-lactame ; les amines sont soient des dérivés de la 7-chloro-4-amino quinoléine ou des amines aliphatiques, allyliques, propargyliques, benzyliques le plus souvent commerciales. Une famille possédant un motif énaminone trifluorométhylée a également été synthétisée car ce motif peut apporter une diversité supplémentaire et la possibilité d'accéder à des complexes métalliques. Des amines portant le motif ferrocène ont été également utilisées. Plus de 80 molécules ont pu être ainsi obtenues et les activités in vitro sur deux souches de P.falciparum (3D7 et W2) ont révélées que les molécules possédant le motif 7-chloro-4-aminoquinoléine étaient en général aussi actives que la chloroquine, voire même plus actives (CI50 proches de 20 nM) avec des indexes de résistance de l'ordre de 1.0-3.5, ne présentaient pas de cytotoxicité (HUVEC) jusqu'à 50 μM et présentaient une stabilité à pH 5.2 et 7.4 pendant 48 heures. Les molécules ne possédant pas le motif présent dans la chloroquine ont démontré des activités plus élevées que la chloroquine avec pour les meilleures des CI50 proches de 10-50 μM ; les γ-hydroxy-γ- lactame-énaminones possédant un motif redox et les γ-hydroxy-γ-lactame incorporant le motif ferrocène sont, par contre, les molécules les plus actives avec des têtes de séries ayant des CI50 proches de 50 à 600 nM. Elles sont également non-cytotoxiques jusqu'à 50 μM. Le mécanisme d'action des têtes de série n'est pas encore connu, ni d'ailleurs l'efficacité in vivo sur un modèle murinThe search for new molecules for the treatment of malaria is still one of important reserch fields. The emergence of resistance to different first-generation antimalarial agents (chloroquine, quinine, mefloquine) is a serious problem in endemic areas requiring sustained effort to be able to offer new treatments in combination with artemisinin derivatives. This project is part of this effort with concern as to propose a new family of molecules which are easy access, low cost and if possible with a novel mechanism of action. We are particularly interested in type derivatives γ-hydroxy-γ-lactam because this pattern is only very little attention in the design of antiparasitic agents that present in a number of naturally occurring molecules and also offers the possibility of a number of structural variations. The synthesis of this type of structures using commercially available tetronic acid initially starts to access to unsaturated γ-lactones (γ-ylidenetetronates) in 3-4 steps, many structure analogues have been proposed from an alkylation or benzylation sequence, aldol and dehydration. The halogenations on such structures then allows access for various palladium-catalyzed coupling (Sonogashira, Stille and Suzuki-Miyaura) with a wide variety of compounds, also an opening to the tetronic acid derivatives having a 1,2,3-triazole moiety from copper catalyzed 1,3-dipolar cycloaddition is shown. Different unsaturated γ-lactones in tetronic series are then reacted with different amines in order to build γ- hydroxy-γ-lactam ring; amines are either derivatives of 7-chloro-4-amino quinoline, aliphatic, allyl, propargyl, benzyl amines, which are usually commercially available. A family with an enaminone with trifluoromethyl moiety were also synthesized for the reason of these can provide additional diversity and the possibility of accessing metal complexes. Amines with the ferrocene moiety ere also used for the lactamization. Thus, more than 80 molecules have been obtained and in vitro activities of two strains of P. falciparum (3D7 and W2) have revealed that molecules with 7-chloro-4-aminoquinoline pattern were generally as active as chloroquine, even more active (IC50 around 20 nM) with better resistance index (1.0-3.5), showed no cytotoxicity (HUVEC) up to 50 μM and showed stability at pH 5.2 and 7.4 for 48 hours. The molecules do not have chloroquine moiety showed less activity than chloroquine with the best IC50 around 10-50 μM, the γ-hydroxy-γ-lactam-enaminones with a redox motif and γ-hydroxy-γ- lactam having ferrocene moiety are the most active seed molecules with IC50 around 50 to 600 nM. They are also non-cytotoxic up to 50 μM. The mechanism of action of seeds is not yet known, nor in vivo efficacy in a mouse model
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Mongin, Florence. "Régiosélectivité des réactions de bromation, d'échange halogène-métal et de couplage croisé sur des dérivés de la 8-hydroxyquinoléine. Application à la synthèse de pyridocarbazoles." Rouen, 1994. http://www.theses.fr/1994ROUES063.
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Les 8-hydroxy et 8-méthoxyquinoléines étudiées peuvent subir une réaction de bromation ; ainsi sont obtenues des quinoléines diversement substituées par des atomes de brome en position 3, 5 et 7. A partir des 5,7-dibromoquinoléines substituées en position 8, un échange brome-lithium sélectif a été réalisé ; la nature du substituant en position 8 modifie l'orientation de cette réaction. La réaction de couplage croisé, appliquée à diverses bromo-8-méthoxyquinoléines, permet de greffer différents groupements. Dans le cas de dibromoquinoléines, une bonne régiosélectivité a été observée. Enfin, de nombreux pyridocarbazoles ont été synthétisés, la réaction de couplage croisé étant utilisée pour créer la jonction entre les cycles quinoléinique et benzénique
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Söderström, Maria. "Local and global contaminants in Swedish waters : studies on PCBs, DDTs, 4,5,6-trichloroguaiacol and their transformation products in fish and sediments." Doctoral thesis, Stockholms universitet, Institutionen för miljökemi, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-104291.
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This thesis is focused on studies on the environmental fate and methodological improvements for determination of the global contaminants, PCBs and DDTs, and locally discharged phenolics, e.g. 4,5,6-trichloroguaiacol (4,5,6-TCG), and their transformation products. 4,5,6-TCG is released from bleached pulp mills, and was chosen as a model substance, to study its fate and effects in aquatic environments. In a brackish water model ecosystem, 4,5,6-TCG was shown to be transformed via demethylation, dechlorination, and methylation reactions. Marine periphyton exposed to 4,5,6-TCG was shown to form demethylated, brominated and dimeric metabolites. Several of these metabolites were identified and quantified. Also more tightly bound chlorophenolics were recovered from the substrate, after harsh extraction procedures had been applied. Conjugates of chlorophenols in fish bile were determined as useful tracers for monitoring effluents from bleached pulp mills, even in areas far from the discharge point. To facilitate calculations of water concentrations, bile to water bioconcentration factors (bBCF-values) were determined for several phenolics, including also alkali-labile chlorocatechols. PCBs and DDTs, were assessed in Swedish lakes with background exposure of these global contaminants. A methodological study focus on the contamination risks of airborne PCBs, during freeze-drying and storage of dry sediment samples. Eutrophication has been proposed to cause lower levels of pollutants in biota in lakes due to biomass dilution but in this thesis examples of higher levels of PCBs in sediment traps, sediment and in perch, and also in higher fluxes of PCBs to the sediment, were observed. Phytoplankton are supposed to be responsible for most of the transport of the contaminants. The composition of DDTs in soil, sediment traps and in dated sediment cores was studied in some detail. PCBs, DDTs, HCB and HCHs were measured in sediments from 100 reference lakes included in the National Swedish Environmental Program. The lakes have a large variation in lake characteristics, representative for different areas in Sweden. A gradient was observed for sPCB with decreasing levels from the south west towards the north. The results suggests that longrange transport is the dominating mechanism for distribution of the contaminants analysed. In this study the levles of PCBs and DDTs were lower in eutrophic lakes than in oligotrophic lakes, in an area with similar atmospheric exposure.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Submitted. Paper 6: Manuscript.
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Ma, Kefeng. "Correlations between structure and phase-properties of phosphonium salts ionic liquid crystals and media for stereoselective brominations and solutue structural studies by NMR spectroscopy." Connect to Electronic Thesis (CONTENTdm), 2009. http://worldcat.org/oclc/458544853/viewonline.
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Galve, Murillo Iñaki. "Síntesis de pirido[2,3-d]pirimidin-7(8H)-onas 2-arilamino sustituidas y derivados." Doctoral thesis, Universitat Ramon Llull, 2013. http://hdl.handle.net/10803/101403.
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Les Cinases de Proteïna (PKs) estan implicades en processos fonamentals de la regulació del cicle cel•lular. L’acumulació d’anomalies als mecanismes de control i el comportament disfuncional que se’n deriva han estat detectats a cèl•lules de diferents teixits afectades per càncer, desordres immunològics, endocrins, nerviosos, neurodegenaratius, cardiovasculars, malalties infeccioses, diabetis, Alzheimer, asma, restenosi, arteriosclerosi, leucèmia, artritis, etc. Però d’entre totes les PKs, les Cinases de Tirosina (TKs) han estat destacades com a l’element central de tots aquests processos i, per tant, han estat objecte d’una gegantina tasca investigadora que n’ha augmentat el seu innegable interès com a diana terapèutica. És per aquest motiu, que el desenvolupament d’inhibidors selectius de TKs ha esdevingut una àrea d’investigació molt activa.
El Laboratori de Síntesi de l’IQS disposa d’una dilatada experiència de síntesi de compostos heterocíclics, especialment pirido[2,3-d]pirimidines, de gran semblança amb coneguts inhibidors de TKs. Malauradament, d’entre tots els building blocks emprats per les estratègies sintétiques desenvolupades, les guanidines (especialment les arilguanidines) sempre han limitat l’espai químic assequible per culpa de la poca diversitat d’aquests reactius comercialment disponibles. Per tant, l’objectiu fonamental d’aquest treball és desenvolupar una metodologia com més genèrica millor que permeti obtenir guanidines i, especialment arilguanidines, i que sigui compatible amb les eines sintètiques disponibles emprades per a l’obtenció massiva de pirido[2,3-d]pirimidines.
Amb aquest objectiu s’optimitza un procediment de guanidinació d’amines amb àcid aminoiminometanosulfònic (AIMSOA, acrònim de l’anglès aminoiminomethanesulfonic acid) en metanol procurant acoblar-lo amb la reacció multicomponent de Victory. Desgraciadament els rendiments amb arilguanidines són baixos com a resultat de llur baixa nucleofília, llur degradació causada pel metanol i per la competència amb el dissolvent de reacció. Com a alternativa, s’assagen protocols de condensació de piridones en 1,4-dioxà per tal d’afavorir la nucleofília d’aquestes arilguanidines. Sorprenentment no s’obtenen directament les piridopirimidines sinó uns intermedis que després d’un procés de transposició de Dimroth donen lloc als heterobicicles esperats amb rendiments força superiors als descrits mitjançant altres metodologies.
En darrer lloc, es planteja i estudia una nova proposta estratègica alternativa al tradicional plantejament del Laboratori de Síntesi de l’IQS per a la síntesi orientada a diversitat. Aquesta proposta implica la construcció de l’esquelet pirido[2,3-d]pirimidínic, seguida de la seva activació mitjançant bromació i diazotizació, i finalment introducció de la diversitat química desitjada. Arran d’aquest estudi s’ha obtingut i aïllat un intermedi de Wheland bicíclic mai descrit fins ara i que posteriorment és transformat per tractament amb DMSO en un terme piropirimidínic dibromat i deshidrogenat a l’anell piridònic. A més a més, s’han desenvolupat eines sintètiques per obtenir sistemes 4-oxopirido[2,3-d]pirimidínics partint de llurs anàlegs 4-amino, metodologies que són una alternativa molt atractiva de les estratègies ja desenvolupades.Las Quinasas de Proteína (PKs) se hallan implicadas en procesos fundamentales de la regulación del ciclo celular. La acumulación de anomalías en los mecanismos de control y el consiguiente comportamiento disfuncional han sido detectados en células de diferentes tejidos afectadas por cáncer, desórdenes inmunológicos, endocrinos, nerviosos, neurodegenarativos, cardiovasculares, enfermedades infecciosas, diabetes, Alzheimer, asma, restenosis, arteriosclerosis, leucemia, artritis, etc. Pero de entre todas las PKs, las Quinasas de Tirosina (TKs) han demostrado ser un elemento central en todos estos procesos y, por tanto, han atraído sobre sí un enorme esfuerzo investigador que ha remarcado, su innegable interés como diana terapéutica. Así pues, el desarrollo de inhibidores selectivos de TKs se ha convertido en un área muy activa de investigación. El Laboratorio de Síntesis del IQS posee amplia experiencia en la síntesis de compuestos heterocíclicos, en especial pirido[2,3-d]pirimidinas, de gran similitud con inhibidores conocidos de TKs. Ahora bien, de todos los building blocks empleados en las estrategias sintéticas desarrolladas, las guanidinas (especialmente las arilguanidinas) siempre han limitado el espacio químico asequible por la poca diversidad de estos reactivos comercialmente asequibles. Por consiguiente, el objetivo fundamental del presente estudio es desarrollar una metodología para la obtención de guanidinas y, en especial de arilguanidinas, que sea compatible con las herramientas sintéticas disponibles para la obtención masiva de pirido[2,3-d]pirimidinas. A tal efecto se optimiza una guanidinación de aminas con ácido aminoiminometanosulfónico en metanol con vistas a poder acoplarlo con la reacción multicomponente de Victory. Desgraciadamente los rendimientos con arilguanidinas son bajos como consecuencia de su baja nucleofilia, su degradación por efecto del metanol y el efecto competente del disolvente de reacción. Para circunvalar este contratiempo se ensayan reacciones de condensación de piridonas en 1,4-dioxano para favorecer la nucleofilia de estas guanidinas. Sorpredentemente no se obtienen directamente las piridopirimidinas sino unos intermedios que tras un proceso de transposición de Dimroth rinden los heterobiciclos deseados con rendimientos bastante superiores a los referidos para otras metodologías. Por último, se propone y estudia una estrategia alternativa de síntesis orientado a diversidad. En este sentido, se construye el esqueleto pirido[2,3-d]pirimidínico para después activarlo mediante bromación y diazotización, y finalmente introducir la diversidad deseada. Fruto de este estudio se ha obtenido y aislado un intermedio de Wheland bicíclico que posteriormente rinde un término piropirimidínico dibromado y deshidrogenado en el anillo piridónico. Adicionalmente, se han desarrollado herramientas sintéticas para la obtención de sistemas 4-oxopirido[2,3-d]pirimidínicos a partir de sus análogos 4-amino.
Protein Kinases (PKs) are involved in basic cellular cycle regulatory mechanisms. Deregulation of those has been found on cells of different tissues with cancer, immunological disorders, endocrine disorders, nervous disorders, neurodegenerative disorders, cardiovascular disorders, infectious diseases, diabetes, Alzheimer syndrome, asthma, restenosis, atherosclerosis, leukemia, arthritis, and more. Among all the PKs huge family, Tyrosine Kinases (TKs) have been described as key point of those regulatory mechanisms and so stated as promising drug targets for treating such diseases. As a result of this biological knowledge, there have been a lot of developments in this field, resulting in some interesting and commercial TKs selective inhibitors. The Laboratori de Síntesi de l’IQS has developed some highly efficient heterocyclic synthetic procedures, especially for the synthesis of pyrido[2,3-d]pyrimidines that are structurally closely related to some well stated TKs inhibitors. Unfortunately, some of the building blocks used in those methodologies have a very narrow commercial variety and are only available from unusual vendors. This is the case for arylguanidines. As a result, the accessible chemical space is shortened. So then, the present work deals with the establishment of general procedures for the synthesis of arylguanidines and how to couple them with our previous described methodologies in order to obtain pyrido[2,3-d]pyrimidine libraries. Aminoiminomethanesulfonic acid (AIMSOA) is selected as guanidination agent and a protocol is optimized by Experimental Design. The coupling of this guanidination with the one-pot multicomponent Victory reaction is also studied. Unfortunately, coupling reaction yields with arylguanidines are very low as a result of lack of nucleophilicity, methanol mediated degradation and nucleophilic competition with this reaction solvent. Pyridone condensation with arylguanidines in 1,4-dioxane is stated as methodological alternative in order to improve nucleophilicity of the arylguanidines. Surprisingly, this procedure does not yield the expected pyridopyrimidines but a family of new, not previously described, heterobicyclic compunds that can be converted to the desired pyridopyrimidines through Dimroth rearrangement. The overall yields for the final pyridopyrimidines are higher with this new procedure than with the previous methodologies. Finally, a new global strategy is developed for the diversity oriented synthesis of 2-arylamino substituted pirido[2,3-d]pyrimidines. Firstly, the heterobicyclic skeleton is build and, secondly, this skeleton is activated by bromination and diazotization. Finally, diversity is introduced by substitution reactions. During this development a pyridopyrimidine Wheland intermediate, never described before ,has been isolated and its structure spectroscopically confirmed. The subsequent treatment of this compound with DMSO yields a new dibrominated pyridopyrimidine dehydrogenated on the pyridone ring. In addition, some synthetic procedures for the conversion of 4-aminopirido[2,3-d]pyrimidines into their 4-oxo analogues have been established. Such methodologies are auseful alternative to our old strategies for the synthesis of this kind of compounds.
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Tsay, Jenq-Yiing, and 蔡政穎. "Bromination of Saturated Thermoplastic Rubber." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/25081638839653928800.
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碩士國立中正大學
化學工程研究所
86
The work is mainly to study the bromination of saturated thermoplastic rubbers which is styrenic copolymer. The experiment will be divided into two parts and discussed as follows separately. First, the reaction were catalytic brominations using bromine and ferric chloride in carbon tetrachloride. According to the NMR spectrum, bromination occurred on aromatic ring. Second, the reaction in cyclohexane can seletively brominated using light or selected radical initiators as promoters of radical bromination, to yield almost exclusively the desired benzylic bromine functionality, via substitution on para-methyl group, and degree of bromination increase as temperature increase.
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Zhong, Guo Chang, and 鍾國昌. "A new chiral brominating agent, (1R, 4S)-(+)-3, 3-dibromocamphor, and its application to the enantioselective bromination." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/85293954839635445403.
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Nour, Mohamed Ali Tawfik. "The synthesis of new polymeric brominating reagents and their applications in the bromination of some cyclic acetals." Rozprawa doktorska, 1995. https://repolis.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=3162.
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Nour, Mohamed Ali Tawfik. "The synthesis of new polymeric brominating reagents and their applications in the bromination of some cyclic acetals." Rozprawa doktorska, 1995. https://delibra.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=3162.
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Shiu, Wu-Zho, and 許武州. "Study on the bromination of 2-alkoxyazulene derivatives." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/97826835894584980189.
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Krosley, Kevin W. "Part I. The identity of the chain propagating radical(s) in photoinitiated benzylic bromination by bromotrichloromethane ; Part II. Chlorine atom abstraction from α- and β-chloroepoxides by the triphenyltin radical." Thesis, 1991. http://hdl.handle.net/1957/37160.
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Ako, Ayuk M. "Kinetics and mechanisms of the aqueous bromination of 3-hydroxypyridines." Thesis, 1991. http://spectrum.library.concordia.ca/3562/1/MM73707.pdf.
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Javed, Bushra C. "The effect of ¯-cyclodextrin on the bromination of organic compounds." Thesis, 1990. http://spectrum.library.concordia.ca/5002/1/MM64698.pdf.
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Bennett, Janice M. "The effect of [alpha]-cyclodextrin on the bromination of phenols." Thesis, 1986. http://spectrum.library.concordia.ca/5779/1/ML32226.pdf.
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Chen, Sz-Chang, and 陳思暢. "Spectroscopic Studies of Chlorination and Bromination of Detonation Diamond Properties." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/28246093297783611338.
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碩士國立東華大學
物理學系
99
In recent years, the emergence of nanodiamonds has gained a lot of research interest and has become a promising material in the field of nanobiotechnology. Combining nanoparticles and biomaterials for applications in drug delivery or bioanalysis has become a main focus of research. Although they find many applications, their agglomeration phenomena and their complicated chemical surface due to the initial processes of detonation still requires to be cracked. Thus, in the present work, we demonstrate the surface functionalization of detonation nanodiamond by chlorination and bromination. Different reaction time with and without microwave treatment and various synthesis conditions have been used to increase the amount of functional groups on the surfaces. The yield of functional group substitution is estimated by using Fourier transform infrared, Raman and X-ray photoelectron spectroscopy. From the results it is concluded that the bromide and chlorides are successfully functionalized on the detonation nanodiamond surfaces and presence of increased amount of functional groups is confirmed. Results of size differences of nanodiamond aggregation after chlorinated and brominated treatment by using scanning electron microscopy and dynamic light scattering is shown.