Academic literature on the topic 'NHC-borane'
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Journal articles on the topic "NHC-borane"
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Liu, Ming, Jan C. Namyslo, Martin Nieger, Mika Polamo, and Andreas Schmidt. "From betaines to anionic N-heterocyclic carbenes. Borane, gold, rhodium, and nickel complexes starting from an imidazoliumphenolate and its carbene tautomer." Beilstein Journal of Organic Chemistry 12 (December 8, 2016): 2673–81. http://dx.doi.org/10.3762/bjoc.12.264.
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The mesomeric betaine imidazolium-1-ylphenolate forms a borane adduct with tris(pentafluorophenyl)borane by coordination with the phenolate oxygen, whereas its NHC tautomer 1-(2-phenol)imidazol-2-ylidene reacts with (triphenylphosphine)gold(I) chloride to give the cationic NHC complex [Au(NHC)2][Cl] by coordination with the carbene carbon atom. The anionic N-heterocyclic carbene 1-(2-phenolate)imidazol-2-ylidene gives the complexes [K][Au(NHC−)2], [Rh(NHC−)3] and [Ni(NHC−)2], respectively. Results of four single crystal analyses are presented.
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Tröger-Müller, Steffen, Markus Antonietti, and Clemens Liedel. "Stability of the zwitterionic liquid butyl-methyl-imidazol-2-ylidene borane." Physical Chemistry Chemical Physics 20, no. 16 (2018): 11437–43. http://dx.doi.org/10.1039/c8cp00311d.
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Lamm, Vladimir, Xiangcheng Pan, Tsuyoshi Taniguchi, and Dennis P. Curran. "Reductions of aldehydes and ketones with a readily available N-heterocyclic carbene borane and acetic acid." Beilstein Journal of Organic Chemistry 9 (April 8, 2013): 675–80. http://dx.doi.org/10.3762/bjoc.9.76.
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Acetic acid promotes the reduction of aldehydes and ketones by the readily available N-heterocyclic carbene borane, 1,3-dimethylimidazol-2-ylidene borane. Aldehydes are reduced over 1–24 h at room temperature with 1 equiv of acetic acid and 0.5 equiv of the NHC-borane. Ketone reductions are slower but can be accelerated by using 5 equiv of acetic acid. Aldehydes can be selectively reduced in the presence of ketones. On a small scale, products are isolated by evaporation of the reaction mixture and direct chromatography.
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Holschumacher, Dirk, Constantin G. Daniliuc, Peter G. Jones, and Matthias Tamm. "Sulfur and SeleniumActivation by Frustrated NHC/B(C6F5)3 Lewis Pairs; Conformational Flexibility of Products." Zeitschrift für Naturforschung B 66, no. 4 (April 1, 2011): 371–77. http://dx.doi.org/10.1515/znb-2011-0406.
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Frustrated Lewis pairs consisting of N-heterocyclic carbenes (NHC) and the borane B(C6F5)3 react with elemental sulfur or selenium to give products of the type NHC-E-B(C6F5)3, where E is S or Se. Three such products, two with sulfur and one with selenium, were characterized by X-ray diffraction and shown to exhibit considerable conformational flexibility, as revealed by differing torsion angles in the atom sequence N-C-E-B-Cipso-Cortho. In the sulfur derivatives, the S-B bonds are all long (ca. 2.05 Å), and the C-S bonds (ca. 1.73 Å) are clearly lengthened compared to imidazole-2-thiones. The Se-B distance of 2.2111 Å is the first selenone-borane bond length to be determined by X-ray analysis.
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Korytiaková, Eva, Niklas O. Thiel, Felix Pape, and Johannes F. Teichert. "Copper(i)-catalysed transfer hydrogenations with ammonia borane." Chemical Communications 53, no. 4 (2017): 732–35. http://dx.doi.org/10.1039/c6cc09067b.
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Highly Z-selective alkyne transfer semihydrogenations and conjugate transfer hydrogenations of enoates can be effected by employing a readily available copper(i)/N-heterocyclic carbene (NHC) complex, [IPrCuOH], in combination with ammonia borane as a H2 equivalent.
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Wang, Chang-Ling, Jie Wang, Ji-Kang Jin, Bin Li, Yee Lin Phang, Feng-Lian Zhang, Tian Ye, et al. "Boryl radical catalysis enables asymmetric radical cycloisomerization reactions." Science 382, no. 6674 (December 2023): 1056–65. http://dx.doi.org/10.1126/science.adg1322.
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The development of functionally distinct catalysts for enantioselective synthesis is a prominent yet challenging goal of synthetic chemistry. In this work, we report a family of chiral N -heterocyclic carbene (NHC)–ligated boryl radicals as catalysts that enable catalytic asymmetric radical cycloisomerization reactions. The radical catalysts can be generated from easily prepared NHC-borane complexes, and the broad availability of the chiral NHC component provides substantial benefits for stereochemical control. Mechanistic studies support a catalytic cycle comprising a sequence of boryl radical addition, hydrogen atom transfer, cyclization, and elimination of the boryl radical catalyst, wherein the chiral NHC subunit determines the enantioselectivity of the radical cyclization. This catalysis allows asymmetric construction of valuable chiral heterocyclic products from simple starting materials.
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Dübek, Gizem, Daniel Franz, Carsten Eisenhut, Philipp J. Altmann, and Shigeyoshi Inoue. "Reactivity of an NHC-stabilized pyramidal hydrosilylene with electrophilic boron sources." Dalton Transactions 48, no. 17 (2019): 5756–65. http://dx.doi.org/10.1039/c9dt00608g.
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An NHC-stabilized three-coordinate hydrosilylene dehydrogenates ammonia borane and forms more stable complexes with BH3, BPh3, BBr3 and BPhBr2 but less stable ones with BF3, and BCl3 for which ligand scrambling occurs.
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Böser, Richard, Lars Denker, and René Frank. "Benzyl Borane NHC Adducts: Beyond B−C Bond Scission." Chemistry – A European Journal 25, no. 45 (July 17, 2019): 10575–79. http://dx.doi.org/10.1002/chem.201902698.
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Hartmann, Caroline E., Václav Jurčík, Olivier Songis, and Catherine S. J. Cazin. "Tandem ammonia borane dehydrogenation/alkene hydrogenation mediated by [Pd(NHC)(PR3)] (NHC = N-heterocyclic carbene) catalysts." Chem. Commun. 49, no. 10 (2013): 1005–7. http://dx.doi.org/10.1039/c2cc38145a.
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Weetman, Catherine, Nozomi Ito, Masafumi Unno, Franziska Hanusch, and Shigeyoshi Inoue. "NHI- and NHC-Supported Al(III) Hydrides for Amine–Borane Dehydrocoupling Catalysis." Inorganics 7, no. 8 (July 24, 2019): 92. http://dx.doi.org/10.3390/inorganics7080092.
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The catalytic dehydrocoupling of amine–boranes has recently received a great deal of attention due to its potential in hydrogen storage applications. The use of aluminum catalysts for this transformation would provide an additional cost-effective and sustainable approach towards the hydrogen economy. Herein, we report the use of both N-heterocyclic imine (NHI)- and carbene (NHC)-supported Al(III) hydrides and their role in the catalytic dehydrocoupling of Me2NHBH3. Differences in the σ-donating ability of the ligand class resulted in a more stable catalyst for NHI-Al(III) hydrides, whereas a deactivation pathway was found in the case of NHC-Al(III) hydrides.
Dissertations / Theses on the topic "NHC-borane"
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Le, Quemener Frédéric. "Utilisation de NHC-Boranes pour la synthèse de nanoparticules et l'amorçage de photopolymérisation en émulsion." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1030/document.
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La première synthèse d'un carbène N-hétérocylique borane (NHC-borane) stable a été réalisée en 1993. Pourtant la découverte de leur vaste potentiel en chimie n'a réellement débuté qu'à partir de 2007. Les domaines d'application de ces composés du bore, stables et facile d'accès, s'étendent de la synthèse d'organique (réduction d'imine, hydroboration de liaisons multiples, médiateurs radicalaires) à la chimie organométallique (couplage de Suzuki-Miyaura) en passant par la chimie des polymères (amorceurs ou co-amorceurs de photopolymérisation). L'objectif de ce projet aura été d'étendre l'application des NHC-boranes dans deux différents systèmes de photopolymérisation. Le premier système étudié a permis l'obtention de matériaux acrylates contenant des nanoparticules métalliques à partir d'un seul composé dans un processus monotope. Le second système visait l'amorçage de réactions de polymérisation en émulsion sous irradiation visible. Nous avons utilisé le pouvoir réducteur des NHC-boranes pour former des nanoparticules d'or ou d'argent directement dans des monomères acrylates. Puis, la formation par le NHC-borane de la matrice polymère contenant les nanoparticules est déclenchée par une irradiation UV. L'analyse par HRTEM a mis en évidence des petites nanoparticules (ca. 10 nm) emprisonnées dans la matrice. Cette méthode présente une approche encore plus directe pour obtenir ce type de matériau plutôt que les procédés multi-étapes déjà existants. Le second système étudié utilise pour la première fois un NHC-borane comme co-amorceur de la polymérisation du styrène ou du méthacrylate de méthyle en émulsion sous irradiation visible. Il en résulte des latex stables, composés de particules de tailles moyennes contrôlées formés à partir de quantités de tensioactifs inférieures à celles utilisées dans des systèmes photoamorcés déjà décrits. Ces systèmes amorcés par une irradiation visibles pourraient être intéressants pour réduire les coûts énergétiques des synthèses et éviter la dégradation de composés thermo- ou UV- fragilesDespite the first synthesis of stable N-heterocyclic carbene (NHC)-boranes occurring as early as 1993, the widespread exploration of their potential in chemistry truly began only in 2007. The versatility of these stable and easily accessible boron compounds has led to their application in organic reactions (imine reduction, multiple bond hydroboration, radical reductions), organometallic reactions (Suzuki- Miyaura cross coupling) and polymerization (initiation or co-initiation of polymerization). The aim of my project was to extend the applicability of NHC-boranes to two different photopolymerization systems. The first aimed to synthesize polymer matrices containing metal nanoparticles in a one pot, one reactant process. The second aimed to perform emulsion polymerizations initiated by visible light. In the first system, the reductive capacity of NHC-boranes was used to generate gold or silver nanoparticles directly in acrylate monomers. Then, the initiating ability of NHC-boranes was triggered by UV light to form the polymer matrix containing embedded nanoparticles. Characterization by HRTEM showed small nanoparticles (ca. 10 nm) successfully contained within the matrix. This method represents a more straightforward approach than obtaining such materials through the multistep processes already reported in literature. In the second system, NHC-boranes were employed for the first time as co-initiators in visible light initiated emulsion polymerization styrene and methyl methacrylate. Stable latexes were generated with controllable particle sizes at lower surfactant concentrations than those used in related light-initiated systems. Such visible light-triggered initiation systems are interesting for reducing energy consumption and avoiding degradation of heat- or UV-sensitive materials
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Subervie, Daniel. "NHC-Boranes : amorceurs de photopolymérisation en émulsion et nouveaux matériaux énergétiques." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1209/document.
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Synthèse et étude de nouveaux NHC-Boranes pour leurs propriétés énergétiques et leurs rôles en tant que photo co-amorceurs pour la photopolymérisation en émulsion.Depuis la première synthèse de complexes N-Hétérocycliques Boranes (NHC-Borane) stables en 1993, une étude plus générale de propriétés et réactivité n’a débuté que dans le milieu des années 2000. Les domaines d’applications de ces composés qui sont des paires de Lewis vont de la synthèse organique (agent réducteur, hydroboration de liaisons multiples) en passant par la chimie radicalaire (remplacement de l’hydrure de tributylétain, hydroboration) ou même en tant qu’amorceur ou co-amorceur de polymérisations.L’objet de cette thèse était d’étendre l’application des NHC-Boranes dans deux domaines précis. Un premier axe porte sur les propriétés hypergoliques amenées par leurs structures inédites. Un second est consacré à l’amorçage de réactions de polymérisations en émulsion et l’obtention de particules hybrides sous irradiation visible.Nous avons choisi et synthétisé de nouvelles cibles polyazotées qui ont montré des propriétés énergétiques potentiellement intéressantes pour l’usage de NHC-Boranes en propulsion solide. L’étude mis en évidence des différentes de réactivités en fonction du squelette du carbène utilisé. De plus, un nouveau type de carbène borane pouvant être utilisé dans différents domaines a été synthétisé.Nous avons aussi amélioré la compréhension du système de photoamorçage déjà proposé en polymérisation en émulsion dans le visible. Des points clés, sur la conception du système et du réacteur ont été améliorés. Nous avons aussi pu remplacer le tensioactif utilisé pour proposer la première photopolymérisation en émulsion Pickering. Il en résulte des latex stables, composés de particules hybrides pouvant former des films potentiellement anti-UV. L’excitation dans le visible, pourrait être utilisée dans le but de réduire les coûts énergétiques et même former d’autres particules inédites en évitant la dégradation de composés thermo ou UV-sensiblesStudy and synthesis of new NHC-Boranes usable as hypergolic fuels and as photo co-initiators for radical emulsion photopolymerizationsThe first N-Heterocyclic Carbene Borane complex (NHC-Borane) was synthetized in 1993, but we had to wait until the mid-2000s before chemists investigated their properties and reactivity. The applications of NHC-Boranes range from organic chemistry (where they are used as reducing agents or for the hydroboration of multiple bonds) to radical chemistry (as replacement of te tributyltin hydride) and radical polymerizations (initiators and co-initiators). We designed and synthetized new Nitrogen-rich NHC-Boranes. The latter are hypergolic and might serve as fuels for solid propulsion. We managed to synthetize several new classed of NHC-Borane which was or could be used in different fields. We also deepened our understanding of the visible light-induced emulsion polymerization, where the NHC-Boranes serve as co-initiators. We could optimize the process and then replaced the surfactant by an inorganic sol to propose the first Pickering emulsion photopolymerization. Stable latexes of hybrid particles have been generated which might be used as sunscreen films, to reduce the energetic footprint of the reactions and/or to access particles made of heat- or UV-sensitive materials
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Toure, Momar Gaya. "Petites variations autour de la chimie de l'imidazole et du bore : de la catalyse aux récepteurs d'anions." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4365.
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La conception et l’élaboration de nouveaux ligands en chimie organométallique évoluent vers le design de ligands multifonctionnels afin d’augmenter l'affinité ligand/métal/substrat et de mimer les catalyseurs de la nature comme les enzymes, en activant de manière synergique les différents partenaires de la réaction. Il existe dans la littérature très peu d’exemples de complexes organométalliques présentant une fonctionnalité acide de Lewis. Dans notre étude, nous avons opté pour l’utilisation d’un atome de bore trivalent pendant. Malgré la forte utilisation des dérivés du bore en catalyse acide de Lewis pour l’activation de divers électrophiles, la conception de tels ligands ambiphiles, pour des complexes organométalliques, a été peu décrite et la réactivité peu étudiée. Ce travail a donc pour but d’explorer et de valider la viabilité de leurs préparations et de leurs utilisations.La première partie de ces travaux a été consacrée au développement de nouveaux complexes bifonctionnels métal/NHC/ester boronique pendant de Pd(II), Rh(I), Ru(II), Au(I) et Cu(I) et leurs applications en catalyse, afin d’accéder à de nouveaux modes d’activation de petites molécules.Dans la deuxième partie, un nouveau mode d’activation efficace de la liaison B-H des carbènes boranes incorporant un bras allylique ou homoallylique par des complexes de rhodium pour accéder à une famille de NHC-boranes cycliques énantioenrichis a été développé.Enfin, la troisième partie constitue la synthèse des travaux sur deux nouvelles familles de cations boronium macrocycliques et leurs applications dans la reconnaissance des anionsConception and elaboration of new ligands in organometallic chemistry evolved towards the design of multi-functional shape to increase the affinity ligand/metal/substrate to mimic nature’s catalysts, and to promote, in most cases, an increasing reactivity and selectivity in the catalytic process. Despite the significant development of N-heterocyclic carbene (NHC) ligands in organometallic chemistry since the last decade, complexes bearing pendant trivalent boron derivatives were so far overlooked.In this context, bifunctional ligands containing NHC and boron moieties have been developed and the corresponding Ag(I), Pd(II), Rh(I), Cu(I) and Ru(II) complexes were designed and prepared for a synergistic activation of both reaction partners by the metal center and the pendant Lewis acidic boron atom.During this work, B−H bond activation of NHC-boranes by a diphosphane-ligated cationic Rh complex was applied in an unprecedented intramolecular enantioselective hydroboration of simple olefins. This study led to a library of enantioenriched cyclic boranes in high yields (up to 94%) with high regio- (up to 100%) and enantioselectivities (er up to 99.2:0.8).As part of this work, new boronium macrocycles were synthesized in high yields and their anion binding ability was evaluated by fluorimetric and 1H NMR titration. These new macrocycles display high binding affinity for halides and oxoanions in the solid state, in solution and in the gas phase
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Toure, Momar Gaya. "Petites variations autour de la chimie de l'imidazole et du bore : de la catalyse aux récepteurs d'anions." Electronic Thesis or Diss., Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4365.
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La conception et l’élaboration de nouveaux ligands en chimie organométallique évoluent vers le design de ligands multifonctionnels afin d’augmenter l'affinité ligand/métal/substrat et de mimer les catalyseurs de la nature comme les enzymes, en activant de manière synergique les différents partenaires de la réaction. Il existe dans la littérature très peu d’exemples de complexes organométalliques présentant une fonctionnalité acide de Lewis. Dans notre étude, nous avons opté pour l’utilisation d’un atome de bore trivalent pendant. Malgré la forte utilisation des dérivés du bore en catalyse acide de Lewis pour l’activation de divers électrophiles, la conception de tels ligands ambiphiles, pour des complexes organométalliques, a été peu décrite et la réactivité peu étudiée. Ce travail a donc pour but d’explorer et de valider la viabilité de leurs préparations et de leurs utilisations.La première partie de ces travaux a été consacrée au développement de nouveaux complexes bifonctionnels métal/NHC/ester boronique pendant de Pd(II), Rh(I), Ru(II), Au(I) et Cu(I) et leurs applications en catalyse, afin d’accéder à de nouveaux modes d’activation de petites molécules.Dans la deuxième partie, un nouveau mode d’activation efficace de la liaison B-H des carbènes boranes incorporant un bras allylique ou homoallylique par des complexes de rhodium pour accéder à une famille de NHC-boranes cycliques énantioenrichis a été développé.Enfin, la troisième partie constitue la synthèse des travaux sur deux nouvelles familles de cations boronium macrocycliques et leurs applications dans la reconnaissance des anionsConception and elaboration of new ligands in organometallic chemistry evolved towards the design of multi-functional shape to increase the affinity ligand/metal/substrate to mimic nature’s catalysts, and to promote, in most cases, an increasing reactivity and selectivity in the catalytic process. Despite the significant development of N-heterocyclic carbene (NHC) ligands in organometallic chemistry since the last decade, complexes bearing pendant trivalent boron derivatives were so far overlooked.In this context, bifunctional ligands containing NHC and boron moieties have been developed and the corresponding Ag(I), Pd(II), Rh(I), Cu(I) and Ru(II) complexes were designed and prepared for a synergistic activation of both reaction partners by the metal center and the pendant Lewis acidic boron atom.During this work, B−H bond activation of NHC-boranes by a diphosphane-ligated cationic Rh complex was applied in an unprecedented intramolecular enantioselective hydroboration of simple olefins. This study led to a library of enantioenriched cyclic boranes in high yields (up to 94%) with high regio- (up to 100%) and enantioselectivities (er up to 99.2:0.8).As part of this work, new boronium macrocycles were synthesized in high yields and their anion binding ability was evaluated by fluorimetric and 1H NMR titration. These new macrocycles display high binding affinity for halides and oxoanions in the solid state, in solution and in the gas phase
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Marques, Paula Fernandes. "New approach to phenanthridine alkaloids by intramolecular radical cyclization." Master's thesis, 2020. http://hdl.handle.net/10362/115203.
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The phenanthridine core is present in several natural products namely the phenanthridine alkaloids. Their synthesis is important in the pharmaceutical industry, so the development of new synthetic methods is welcomed by them.
Radical reactions are involved in the synthesis of several natural products, among them the phenanthridine alkaloids. The use of tributyltin hydride and azobisisobutyronitrile is a common approach for the thermal generation of radicals. Beyond being an effective method, they have associated the toxic effects of the tin.
For the past few years, N-heterocyclic carbene-boranes have being used in radical reactions, as radical mediators. Applications in radical reductions and, more recently, in intramolecular cyclizations have been reported.
Here we report studies with N-heterocyclic carbene-boranes for the intramolecular cyclization of appropriated substrates for the synthesis of the phenanthridines core. For that, the substrates used include secondary and tertiary amines, an amide, and an ether. Attempts has been made to synthesise a heteroatom free substrate in order to understand the effect of the heteroatoms in the reaction, but without success. Two different N-heterocyclic carbene-boranes were synthesized based on imidazolium salts, the (1,3-dimethylimidazolium-2-yl)trihydroborate and the (3-ethyl-1-methylimidazolium-2-yl)trihydroborate.
The reactions yields were below expectations, however the cyclization products were obtained. No reduction products were identified, showing the difficulty of the boranes to react with the substrate. It was identified a complex between a tertiary amide substrate and the borane, which may be the reason for the low yields. In the reaction with the ether it seems that the complex with the NHC-borane is also formed.
It was also identified an adduct between the borane and the thiophenol, when this last one was used as co-adjuvant. The formation of that adduct should be the reason why the reactions with thiophenol had a lower yield.Unfortunately, all the attempts to increase the yield were unsuccessful.
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Tambutet, Guillaume. "Synthèse stéréosélective de centres tertiaires et quaternaires par voie radicalaire et leur application à la synthèse d’analogues de nucléosides et de polypropionate." Thèse, 2017. http://hdl.handle.net/1866/20962.
Full textBook chapters on the topic "NHC-borane"
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Lambert, Tristan H. "Functional Group Reduction." In Organic Synthesis. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780190200794.003.0010.
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The reduction of azobenzene 1 with catalyst 2 was reported (J. Am. Chem. Soc. 2012, 134, 11330) by Alexander T. Radosevich at Pennsylvania State University, representing a unique example of a nontransition metal-based two-electron redox catalysis platform. Wolfgang Kroutil at the University of Graz found (Angew. Chem. Int. Ed. 2012, 51, 6713) that diketone 4 was converted to piperidinium 5 with very high stereoselectivity using a transaminase followed by reduction over Pd/C. Dennis P. Curran at the University of Pittsburgh reported (Org. Lett. 2012, 14, 4540) that NHC-borane 7 is a convenient reducing agent for aldehydes and ketones, showing selectivity for the former as in the monoreduction of 6 to 8. A catalytic reduction of esters to ethers with Fe3(CO)12 and TMDS, as in the conversion of 9 to 10, was developed (Chem. Commun. 2012, 48, 10742) by Matthias Beller at the Leibniz-Institute for Catalysis. Meanwhile, iridium catalysis was used (Angew. Chem. Int. Ed. 2012, 51, 9422) by Maurice Brookhart at the University of North Carolina at Chapel Hill for the reduction of esters to aldehydes with diethylsilane (e.g., 11 to 12). As an impressive example of selective reduction, Ohyun Kwon at UCLA reported (Org. Lett. 2012, 14, 4634) the conversion of ester 13 to aldehyde 14, leaving the malonate moiety intact. The cobalt complex 16 was found (Angew. Chem. Int. Ed. 2012, 51, 12102) by Susan K. Hanson at Los Alamos National Laboratory to be an effective catalyst for C=O, C=N, and C=C bond hydrogenation, including the conversion of alkene 15 to 17. The use of frustrated Lewis pair catalysis for the low-temperature hydrogenation of alkenes such as 18 was developed (Angew. Chem. Int. Ed. 2012, 51, 10164) by Stefan Grimme at the University of Bonn and Jan Paradies the Karlsruhe Institute of Technology. Guanidinium nitrate was found (Chem. Commun. 2012, 48, 6583) by Kandikere Ramaiah Prabhu at the Indian Institute of Science to catalyze the hydrazine-based reduction of alkenes such as 20. The hydrogenation of thiophenes is difficult for a number of reasons, but now Frank Glorius at the University of Münster has developed (J. Am. Chem. Soc. 2012, 134, 15241) an effective system for the highly enantioselective catalytic hydrogenation of thiophenes and benzothiophenes, including 22.
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Lambert, Tristan H. "Construction of Single Stereocenters." In Organic Synthesis. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780190200794.003.0037.
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James L. Leighton at Columbia University reported (Nature 2012, 487, 86) that the commercially available allylsilane 2 allylated acetoacetone (1) to furnish the enantioenriched tertiary carbinol 3. Alexander T. Radosevich demonstrated (Angew. Chem. Int. Ed. 2012, 51, 10605) that diazaphospholidine 5 induced the formal reductive insertion of 3,5-dinitrobenzoic acid to α-ketoester 4 to generate adduct 6 enantioselectively. Tehshik P. Yoon at the University of Wisconsin at Madison found (J. Am Chem. Soc. 2012, 134, 12370) that aminoalcohol derivative 9 could be prepared via an asymmetric iron-catalyzed oxyamination of diene 7 using oxaziridine 8. A procedure for the desymmetrization of 1,3-difluoropropanol 10 by nucleophilic displacement of an unactivated aliphatic fluoride to generate 11 was reported (Angew. Chem. Int. Ed. 2012, 51, 12275) by Günter Haufe at the University of Münster and Norio Shibata at the Nagoya Institute of Technology. An innovative procedure for the amination of unactivated olefins involving an ene reaction/[ 2,3]-rearrangement sequence (e.g., 12 to 13) was developed (J. Am. Chem. Soc. 2012, 134, 18495) by Uttam K. Tambar at the University of Texas Southwestern Medical Center. James P. Morken at Boston College demonstrated the stereospecific amination of borane 14 with methoxylamine to produce 15. The conversion of β-ketoester 16 to 18 by amination with 17 under oxidative conditions was reported (J. Am. Chem. Soc. 2012, 134, 18948) by Javier Read de Alaniz at the University of California at Santa Barbara. The electrophilic amination of silyl ketene acetal 19 with a functionalized hydroxylamine reagent to produce 20 was disclosed (Angew. Chem. Int. Ed. 2012, 51, 11827) by Koji Hirano and Masahiro Miura at Osaka University. Erick M. Carreira at ETH Zürich developed (Angew. Chem. Int. Ed. 2012, 51, 8652) the enantioconvergent thioetherification of alcohol 21 to produce 23 with high branched to linear selectivity and ee. The asymmetric conjugate addition of 2-aminothiophenol 25 to 24 catalyzed by mesitylcopper in the presence of ligand 26 was developed (Angew. Chem. Int. Ed. 2012, 51, 8551) by Naoya Kumagai and Masakatsu Shibasaki at the Institute of Microbial Chemistry in Tokyo. The enantioselective conversion of aldehyde 28 to α-fluoride 30 under catalysis by NHC 29 was developed (Angew. Chem. Int. Ed. 2012, 51, 10359) by Zhenyang Lin and Jianwei Sun at the Hong Kong University of Science and Technology.