Conecte-se

Bibliografias temáticas / Spirocyclic molecules / Artigos de revistas

Siga este link para ver outros tipos de publicações sobre o tema: Spirocyclic molecules.

Artigos de revistas sobre o tema "Spirocyclic molecules"

Autor: Grafiati

Publicado: 31 de março de 2023

Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos

Selecione um tipo de fonte:

Veja os 50 melhores artigos de revistas para estudos sobre o assunto "Spirocyclic molecules".

Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.

Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.

Veja os artigos de revistas das mais diversas áreas científicas e compile uma bibliografia correta.

1

Fominova, Kateryna, Taras Diachuk, Dmitry Granat, Taras Savchuk, Vladyslav Vilchynskyi, Oleksiy Svitlychnyi, Vladyslav Meliantsev et al. "Oxa-spirocycles: synthesis, properties and applications". Chemical Science 12, n.º 34 (2021): 11294–305. http://dx.doi.org/10.1039/d1sc03615g.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

2

Benabdallah, Mohammed, Oualid Talhi, Fatiha Nouali, Nouredine Choukchou-Braham, Khaldoun Bachari e Artur M. S. Silva. "Advances in Spirocyclic Hybrids: Chemistry and Medicinal Actions". Current Medicinal Chemistry 25, n.º 31 (16 de outubro de 2018): 3748–67. http://dx.doi.org/10.2174/0929867325666180309124821.

Texto completo da fonte

Resumo:

The present review deals with the progress in medicinal chemistry of spirocyclic compounds, a wider class of natural and synthetic organic molecules, defined as a hybrid of two molecular entities covalently linked via a unique tetrahedral carbon. This spiro central carbon confers to the molecules a tridimensional structurally oriented framework, which is found in many medicinally relevant compounds, a well-known example is the antihypertensive spironolactone. Various bioactive natural products possess the privileged spiro linkage and different chemo-types thereof become synthetically accessible since the 20th century. Actually, there has been a growing interest in the synthesis of heterocyclic hybrids gathered via a spiro carbon. Most of these combinations are two moieties in one scaffold being able to interfere with biological systems through sequential mechanisms. Spirocyclic hybrids containing indole or oxindole units are compounds exhibiting higher interaction with biological receptors by protein inhibition or enzymatic pathways and their recognition as promising anticancer agents in targeted chemotherapy is foreseen. These specific, low-weight and noncomplex spirocyclic hybrids are potent inhibitors of SIRT1, Mdm2–p53 and PLK4, showing affinity for anaplastic lymphoma kinase (ALK) receptor. They are also known as excellent DNA binders, acting on cellular division by arresting the cell cycle at different phases and inducing apoptotic cell death. A structural diversity of spirocyclic hybrids has proved neuroprotective effects, anti-HIV, antiviral and antibacterial activities. Hundred of papers are mentioned in this review underlying chemical issues and pharmacological potencies of spiro compounds, which render them impressive synthetic hits for innovative drug conception.

Estilos ABNT, Harvard, Vancouver, APA, etc.

3

Paquette, Leo A. "Spirocyclic Restriction of Nucleosides". Australian Journal of Chemistry 57, n.º 1 (2004): 7. http://dx.doi.org/10.1071/ch03267.

Texto completo da fonte

Resumo:

The concept of spirocyclic restriction as applied broadly to the field of nucleoside mimics makes possible the generation of diastereomeric pairs configured with a syn- or anti-oriented hydroxyl substituent at C5′. The development of concise synthetic routes to spiro-fused nucleosides bearing all possible natural bases and expectedly capable of enforcing a conformation favourable for duplex formation on incorporation into oligomers represents a significant new direction in the design of antisense molecules. The present overview describes the convenient approaches that have been developed in this laboratory for accessing varied members of this class, including analogues that feature sulfur and carbon at the apical position.

Estilos ABNT, Harvard, Vancouver, APA, etc.

4

Shen, Guo-Liang, Jing Sun e Chao-Guo Yan. "Construction of dispirocyclohexyl-3,3′-bisoxindole and dispirocyclopentyl-3,3′-bisoxindole via domino cycloaddition reactions of N-benzylbenzimidazolium salts with 2-(2-oxoindolin-3-ylidene)acetates". RSC Advances 5, n.º 6 (2015): 4475–83. http://dx.doi.org/10.1039/c4ra13760d.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

5

Kappen, Lizzy S., Yiqing Lin, Graham B. Jones e Irving H. Goldberg. "Probing DNA Bulges with Designed Helical Spirocyclic Molecules†". Biochemistry 46, n.º 2 (janeiro de 2007): 561–67. http://dx.doi.org/10.1021/bi061744d.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

6

G. Keller, Sascha, Mako Kamiya e Yasuteru Urano. "Recent Progress in Small Spirocyclic, Xanthene-Based Fluorescent Probes". Molecules 25, n.º 24 (16 de dezembro de 2020): 5964. http://dx.doi.org/10.3390/molecules25245964.

Texto completo da fonte

Resumo:

The use of fluorescent probes in a multitude of applications is still an expanding field. This review covers the recent progress made in small molecular, spirocyclic xanthene-based probes containing different heteroatoms (e.g., oxygen, silicon, carbon) in position 10′. After a short introduction, we will focus on applications like the interaction of probes with enzymes and targeted labeling of organelles and proteins, detection of small molecules, as well as their use in therapeutics or diagnostics and super-resolution microscopy. Furthermore, the last part will summarize recent advances in the synthesis and understanding of their structure–behavior relationship including novel computational approaches.

Estilos ABNT, Harvard, Vancouver, APA, etc.

7

Holovatiuk, V. M., O. A. Brazhko e V. I. Kashkovsky. "ВИВЧЕННЯ ГОСТРОЇ ТОКСИЧНОСТІ ТА АНАЛГЕТИЧНОЇ АКТИВНОСТІ НОВИХ СПІРОЦИКЛІЧНИХ ПОХІДНИХ ПІРАЗОЛІДИН-3,5-ДІОНУ". Biological Bulletin of Bogdan Chmelnitskiy Melitopol State Pedagogical University 6, n.º 3 (4 de novembro de 2016): 149–53. http://dx.doi.org/10.15421/201681.

Texto completo da fonte

Resumo:

<p>We presented the results of acute toxicity and analgesic activity research of the new spirocyclic pyrazolidine-3,5-dione derivatives. We studied the acute toxicity of spirodiazolidines with QSAR analysis by QuS computer design and experimentally on mammalian (mice). These compounds had low toxicity and toxic values that decreased with introduction of methyl substituent in cyclopentenic ring and other substituents in compound aromatic fragments. The acute toxicity values that were obtained by nonexperimental and experimental methods had similar magnitudes, and this will allow to apply the computer prognosis in further investigations and design of new bioactive molecules. We also carried out the research of analgesic activity of new spirocyclic pyrazolidinedione derivatives. We proved that some compounds of the studied range have significant analgesic activity to be competed with well-known pyrazolone containing drug ‘Analgin’.</p>

Estilos ABNT, Harvard, Vancouver, APA, etc.

8

Innocenti, Riccardo, Elena Lenci, Gloria Menchi e Andrea Trabocchi. "Combination of multicomponent KA2 and Pauson–Khand reactions: short synthesis of spirocyclic pyrrolocyclopentenones". Beilstein Journal of Organic Chemistry 16 (12 de fevereiro de 2020): 200–211. http://dx.doi.org/10.3762/bjoc.16.23.

Texto completo da fonte

Resumo:

The Cu-catalyzed multicomponent ketone–amine–alkyne (KA2) reaction was combined with a Pauson–Khand cycloaddition to give access of unprecedented constrained spirocyclic pyrrolocyclopentenone derivatives following a DOS couple-pair approach. The polyfunctional molecular scaffolds were tested on the cyclopentenone reactivity to further expand the skeletal diversity, demonstrating the utility of this combined approach in generating novel spiro compounds as starting material for the generation of chemical libraries. The chemoinformatics characterization of the newly-synthesized molecules gave evidence about structural and physicochemical properties with respect to a set of blockbuster drugs, and showed that such scaffolds are drug-like but more spherical and three-dimensional in character than the drugs.

Estilos ABNT, Harvard, Vancouver, APA, etc.

9

Chernyshov, Vladimir V., Yuri V. Gatilov, Olga I. Yarovaya, Igor P. Koskin, Spartak S. Yarovoy, Konstantin A. Brylev e Nariman F. Salakhutdinov. "The first example of the stereoselective synthesis and crystal structure of a spirobicycloquinazolinone based on (–)-fenchone and anthranilamide". Acta Crystallographica Section C Structural Chemistry 75, n.º 12 (26 de novembro de 2019): 1675–80. http://dx.doi.org/10.1107/s2053229619015766.

Texto completo da fonte

Resumo:

The possibility of a single-stage solvent-free stereoselective synthesis of a spirocyclic compound from the natural bicyclic monoterpenoid (−)-fenchone and anthranilamide has been shown for the first time. The molecular and crystal structure of (1R,2S,4S)-1,3,3-trimethyl-1′H-spiro[bicyclo[2.2.1]heptane-2,2′-quinazolin]-4′(3′H)-one, C17H22N2O, was established by X-ray diffraction though the chirality was assumed via the known reactant connectivity and 1H and 13C NMR spectroscopy. It has shown that in the molecule, for steric reasons, there is an elongation of the Me2C—C(N)N bond to 1.603 (5) Å. The formation of dimers via N—H...O=C hydrogen bonds with an interaction energy of 93.30 kJ mol−1 and through cavities (33.7% of the unit-cell volume) was established in the packing of the molecules. There are no π-stacking interactions in the structure.

Estilos ABNT, Harvard, Vancouver, APA, etc.

10

Linden, Anthony, Grzegorz Mlostoń, Paulina Grzelak e Heinz Heimgartner. "Chemo- and regioselective [3 + 2]-cycloadditions of thiocarbonyl ylides: crystal structures of trans-8-benzoyl-1,1,3,3-tetramethyl-7-trifluoromethyl-5-thiaspiro[3.4]octan-2-one and trans-3-benzoyl-2,2-diphenyl-4-(trifluoromethyl)tetrahydrothiophene". Acta Crystallographica Section E Crystallographic Communications 74, n.º 12 (6 de novembro de 2018): 1705–9. http://dx.doi.org/10.1107/s2056989018015335.

Texto completo da fonte

Resumo:

The title compounds, C19H21F3O2S and C24H19F3OS, were prepared via chemo- and regioselective [3 + 2]-cycloadditions of the respective thiocarbonyl ylides (thiocarbonyl S-methanides), generated in situ, with (E)-4,4,4-trifluoro-1-phenylbut-2-en-1-one. The thiophene ring in the crystal structure of each compound has an envelope conformation. The largest differences between the two molecular structures is in the bond lengths about the quaternary C atom of the thiophene ring; in the spirocyclic structure, the C—C bonds to the spiro C atom in the cyclobutane ring are around 1.60 Å, although this is also observed in related structures. In the same structure, weak intermolecular C—H...X (X = S, O) interactions link the molecules into extended ribbons running parallel to the [001] direction. In the other structure, weak C—H...π interactions link the molecules into sheets parallel to the (010) plane.

Estilos ABNT, Harvard, Vancouver, APA, etc.

11

Thompson, Kirstie A., Ronita Mathias, Daeok Kim, Jihoon Kim, Neel Rangnekar, J. R. Johnson, Scott J. Hoy et al. "N-Aryl–linked spirocyclic polymers for membrane separations of complex hydrocarbon mixtures". Science 369, n.º 6501 (16 de julho de 2020): 310–15. http://dx.doi.org/10.1126/science.aba9806.

Texto completo da fonte

Resumo:

The fractionation of crude-oil mixtures through distillation is a large-scale, energy-intensive process. Membrane materials can avoid phase changes in such mixtures and thereby reduce the energy intensity of these thermal separations. With this application in mind, we created spirocyclic polymers with N-aryl bonds that demonstrated noninterconnected microporosity in the absence of ladder linkages. The resulting glassy polymer membranes demonstrated nonthermal membrane fractionation of light crude oil through a combination of class- and size-based “sorting” of molecules. We observed an enrichment of molecules lighter than 170 daltons corresponding to a carbon number of 12 or a boiling point less than 200°C in the permeate. Such scalable, selective membranes offer potential for the hybridization of energy-efficient technology with conventional processes such as distillation.

Estilos ABNT, Harvard, Vancouver, APA, etc.

12

Swamy, K. C. Kumara, Roberta O. Day, Joan M. Holmes e Robert R. Holmes. "Pentacoordinated molecules. 81. Conformational preferences of spirocyclic pentaoxyphosphoranes varying in ring size". Journal of the American Chemical Society 112, n.º 16 (agosto de 1990): 6095–103. http://dx.doi.org/10.1021/ja00172a028.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

13

Langer, Peter. "Synthesis of Purines and Related Molecules by Cyclization Reactions of Heterocyclic Enamines". Synlett 33, n.º 05 (22 de outubro de 2021): 440–57. http://dx.doi.org/10.1055/s-0040-1719845.

Texto completo da fonte

Resumo:

AbstractA great variety of pharmacologically relevant fluorinated purine analogues are available by cyclization reactions of heterocyclic enamines with 1,3-dielectrophiles. The reactions usually proceed with excellent regioselectivities. As electrophiles, 1,3-diketones, enaminones or 3-chloro-2-en-1-ones were used. Other synthetic strategies are based on inverse-electron-demand Diels–Alder reactions of heterocyclic enamines with triazines. Purine analogues were further functionalized by transition-metal-catalyzed CH-coupling reactions or oxidative cyclizations, giving rise to more complex polycyclic products. Amidino-C-glycosides in their reactions with 1,3-dielectrophiles afforded pyrimidine-C-glycosides. Multicomponent reactions of heterocyclic enamines afforded complex products, including spirocyclic derivatives.1 Introduction2 1,3-Diketones3 Enaminones4 3-Chloro-2-en-1-ones5 Triazines6 Transition-Metal-Catalyzed Functionalizations7 Pyrimidine-C-Nucleosides8 Multicomponent Reactions9 Conclusions

Estilos ABNT, Harvard, Vancouver, APA, etc.

14

Pappin, Brighid B., Stephan M. Levonis, Peter C. Healy, Milton J. Kiefel, Michela I. Simone e Todd A. Houston. "Crystallization-induced amide bond formation creates a boron-centered spirocyclic system". Heterocyclic Communications 23, n.º 3 (27 de junho de 2017): 167–69. http://dx.doi.org/10.1515/hc-2017-0023.

Texto completo da fonte

Resumo:

AbstractThe 5-nitrosalicylate ester of 2-acetamidophenylboronic acid (C15H10BN2O6) is formed under crystallization conditions from the 5-nitrosalicylate ester of 2-aminophenylboronic acid. The boron at the center of this structure exists as a tetrahedral complex produced by a dative bond with the amide carbonyl. The perpendicular shape produces an unusual packing structure including a bifurcated hydrogen bond between the amide hydrogen and carbonyl groups on two neighboring molecules. We propose that this reaction occurs due to increased Lewis acidity of the nitrosalicylate ester of 2-aminophenylboronic acid.

Estilos ABNT, Harvard, Vancouver, APA, etc.

15

Zaytseva, Elena, e Dmitrii Mazhukin. "Spirocyclic Nitroxides as Versatile Tools in Modern Natural Sciences: From Synthesis to Applications. Part I. Old and New Synthetic Approaches to Spirocyclic Nitroxyl Radicals". Molecules 26, n.º 3 (28 de janeiro de 2021): 677. http://dx.doi.org/10.3390/molecules26030677.

Texto completo da fonte

Resumo:

Spirocyclic nitroxyl radicals (SNRs) are stable paramagnetics bearing spiro-junction at α-, β-, or γ-carbon atom of the nitroxide fragment, which is part of the heterocyclic system. Despite the fact that the first representatives of SNRs were obtained about 50 years ago, the methodology of their synthesis and their usage in chemistry and biochemical applications have begun to develop rapidly only in the last two decades. Due to the presence of spiro-function in the SNRs molecules, the latter have increased stability to various reducing agents (including biogenic ones), while the structures of the biradicals (SNBRs) comprises a rigid spiro-fused core that fixes mutual position and orientation of nitroxide moieties that favors their use in dynamic nuclear polarization (DNP) experiments. This first review on SNRs will give a glance at various strategies for the synthesis of spiro-substituted, mono-, and bis-nitroxides on the base of six-membered (piperidine, 1,2,3,4-tetrahydroquinoline, 9,9′(10H,10H′)-spirobiacridine, piperazine, and morpholine) or five-membered (2,5-dihydro-1H-pyrrole, pyrrolidine, 2,5-dihydro-1H-imidazole, 4,5-dihydro-1H-imidazole, imidazolidine, and oxazolidine) heterocyclic cores.

Estilos ABNT, Harvard, Vancouver, APA, etc.

16

Paquette, Leo A., George A. O'Doherty, Benjamin L. Miller, Robin D. Rogers, Arnold L. Rheingold e Steven L. Geib. "Isodicyclopentadienes and related molecules. 48. Stereochemically uniform mode of iron carbonyl complexation to spirocyclic isodicyclopentadienes". Organometallics 8, n.º 9 (setembro de 1989): 2167–72. http://dx.doi.org/10.1021/om00111a012.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

17

Hans, Johannes, Roberta O. Day e Robert R. Holmes. "Pentacoordinated molecules. 89. Hydrogen-bonded chain and dimer formations of spirocyclic tetraoxyphosphoranes possessing phosphorinane chair conformations". Inorganic Chemistry 30, n.º 20 (outubro de 1991): 3928–36. http://dx.doi.org/10.1021/ic00020a028.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

18

Holmes, Robert R., Soheila Shafieezad, V. Chandrasekhar, Arjun C. Sau, Joan M. Holmes e Roberta O. Day. "Pentacoordinated molecules. 70. New five- and six-coordinated anionic tin(IV) complexes. Molecular structure of spirocyclic stannates with mixed ligands". Journal of the American Chemical Society 110, n.º 4 (fevereiro de 1988): 1168–74. http://dx.doi.org/10.1021/ja00212a027.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

19

Holmes, Robert R., Roberta O. Day, V. Chandrasekhar e Joan M. Holmes. "Pentacoordinated molecules. 61. Synthesis and molecular structure of five-coordinated spirocyclic anionic silicates containing tert-butyl groups. Hydrogen-bonding effects". Inorganic Chemistry 24, n.º 13 (junho de 1985): 2009–15. http://dx.doi.org/10.1021/ic00207a012.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

20

Holmes, Robert R., Roberta O. Day, Arjun C. Sau e Joan M. Holmes. "Pentacoordinated molecules. 63. Distortion coordinate for nonrigid five-coordinated germanium. Synthesis and molecular structure of spirocyclic anionic methylgermanates varying in ring composition". Inorganic Chemistry 25, n.º 5 (fevereiro de 1986): 600–606. http://dx.doi.org/10.1021/ic00225a005.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

21

Holmes, Robert R., K. C. Kumara Swamy, Joan M. Holmes e Roberta O. Day. "Pentacoordinated molecules. 84. Conformational effects of ring fusion and heteroatom substitution in six-membered rings of spirocyclic oxyphosphoranes". Inorganic Chemistry 30, n.º 5 (março de 1991): 1052–62. http://dx.doi.org/10.1021/ic00005a033.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

22

HANS, J., R. O. DAY e R. R. HOLMES. "ChemInform Abstract: Pentacoordinated Molecules. Part 89. Hydrogen-Bonded Chain and Dimer Formations of Spirocyclic Tetraoxyphosphoranes Possessing Phosphorinane Chair Conformations." ChemInform 23, n.º 3 (22 de agosto de 2010): no. http://dx.doi.org/10.1002/chin.199203214.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

23

Dietz, Jochen, Ulrich Müller, Volker Müller e Kurt Dehnicke. "Die Kristallstrukturen von (NEt4+)2[Se52- · 1/2 Se6·Se7] und von (NPr4)2Se11 / The Crystal Structures of (NEt4+)2[Se52- · 1/2 Se6 · Se7] and (NPr4)2Se11". Zeitschrift für Naturforschung B 46, n.º 10 (1 de outubro de 1991): 1293–99. http://dx.doi.org/10.1515/znb-1991-1003.

Texto completo da fonte

Resumo:

The title compounds have been prepared by the reactions of a potassium diselenide solution in DMF with excess selenium in the presence of tetraethyl and tetrapropyl ammonium chloride, respectively. They were characterized by X-ray crystal structure determinations.(NEt4+)2[Se52-·1 /2 Se6 · Se7]: Space group PĪ, Z = 2, 2514 observed unique reflections, R = 0.085. Lattice dimensions at —40 °C: a = 957.7(4), b = 1384.2(4), c = 1545.3(7) pm, α = 107.32(3)°, β = 97.27(4)°, γ = 105.94(3)°. The compound has an ionic structure of NEt4+ ions and chains of pentaselenide ions, which are associated with Se6 and Se7, ring molecules, forming layers parallel to (110).(NPr4)2Se11: Space group C2/c, Ζ = 4, 2198 observed unique reflections, R = 0.082. Lattice dimensions at —40 °C: a = 2364.7(5), b = 1206.8(2), c = 1609.6(3) pm, β = 118.74(3)°. The compound consists of cations (N(C3H7)4+ and spirocyclic anions Se112-, in which two Se6 rings having chair conformation are linked by a common Se atom with planar coordination. There are no short contacts between the S112- ions.

Estilos ABNT, Harvard, Vancouver, APA, etc.

24

Holmes, Robert R., Roberta O. Day, Arjun C. Sau, Charles A. Poutasse e Joan M. Holmes. "Pentacoordinated molecules. 58. Stereochemically nonrigid five-coordinated germanates. Synthesis and structure of hydroxy- and halo-containing spirocyclic germanium(IV) complexes". Inorganic Chemistry 24, n.º 2 (janeiro de 1985): 193–99. http://dx.doi.org/10.1021/ic00196a015.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

25

Villabona, Marc, Marina Benet, Silvia Mena, Rabih O. Al-Kaysi, Jordi Hernando e Gonzalo Guirado. "Multistimuli-Responsive Fluorescent Switches Based on Spirocyclic Meisenheimer Compounds: Smart Molecules for the Design of Optical Probes and Electrochromic Materials". Journal of Organic Chemistry 83, n.º 16 (13 de junho de 2018): 9166–77. http://dx.doi.org/10.1021/acs.joc.8b01211.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

26

HOLMES, R. R., K. C. K. SWAMY, J. M. HOLMES e R. O. DAY. "ChemInform Abstract: Pentacoordinated Molecules. Part 84. Conformational Effects of Ring Fusion and Heteroatom Substitution in Six-Membered Rings of Spirocyclic Oxyphosphoranes." ChemInform 22, n.º 25 (23 de agosto de 2010): no. http://dx.doi.org/10.1002/chin.199125208.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

27

Day, Roberta O., K. C. Kumara Swamy, Lisa Fairchild, Joan M. Holmes e Robert R. Holmes. "Pentacoordinated molecules. 85. Influence of hydrogen bonding on the formation of boat and chair conformations of six-membered rings in spirocyclic tetraoxyphosphoranes". Journal of the American Chemical Society 113, n.º 5 (fevereiro de 1991): 1627–35. http://dx.doi.org/10.1021/ja00005a028.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

28

Yang, Jun, Bo-Wen Pan, Lin Chen, Ying Zhou e Xiong-Li Liu. "Recent advances in organocatalytic cascade reactions for enantioselective synthesis of chiral spirolactone skeletons". Chemical Synthesis 3, n.º 1 (2023): 7. http://dx.doi.org/10.20517/cs.2022.38.

Texto completo da fonte

Resumo:

Chiral spirolactones, including spiropropyllactones, spirobutyrolactones, and spirovalerolactones, are important heterocyclic frameworks that attracted the attention of organic and medicinal chemists because these motifs constitute the core structure of several natural products and bioactive molecules. The absolute configuration and the substituents on the fully substituted spirocyclic stereocenter of the lactone can potentially enhance specificity for ligand-protein binding and enhance bioavailability, potency, and metabolic stability. So, intensive attention from chemists has been paid to the synthetic methods leading to such prominent structural motifs. The synthetic methods can be divided into two main classes. The first approach takes advantage of the presence of the existing lactone structure and focuses on its functionalization. The second approach is the lactone framework constructed from various precursors in a direct spirolactonization reaction. In this review, for convenience in reading, the recent advances in the synthesis of spirolactones are summarized and discussed according to the two major organocatalytic asymmetric synthetic routes: (i) using the lactone-related frameworks as building blocks; and (ii) direct spirolactonization reaction using various reagents. This review also describes both the mechanisms and related transformations, and gives some insights into challenging issues in this research field, which will enlighten the future development of this field.

Estilos ABNT, Harvard, Vancouver, APA, etc.

29

Kumar, Nakul, Gajendra Kumar Inwati, Emad M. Ahmed, Chhagan Lal, Bharat Makwana, Virendra K. Yadav, Saiful Islam, Hyun-Jo Ahn, Krishna K. Yadav e Byong-Hun Jeon. "Modified 7-Chloro-11H-indeno[1,2-b]quinoxaline Heterocyclic System for Biological Activities". Catalysts 12, n.º 2 (11 de fevereiro de 2022): 213. http://dx.doi.org/10.3390/catal12020213.

Texto completo da fonte

Resumo:

Recent advances in functionalized organic Spiro heterocyclic compounds composed of nitrogen bonded five- and six-membered rings have been made, establishing them as a synthetic target in organic-based biomedical applications. In this work, we report a synthesis of spirocyclic compounds under a one-pot reaction using 1,3-dipolar cycloaddition in a regio and diastereoselective manner. The higher atomic economy with higher yield (95%) and regio and stereoselectivity were achieved by a multi-component reaction of L-proline (1), Indenoquinoxaline (2), and the dipolarophile of malononitrile (3) solvents followed by reflux conditions. The reaction intermediate comprised azomethineylides derived from reactive primary amines, and the spiro derivatives were synthesized up to a ≈ 95% yield. The structural and characteristic chemical components of the as-prepared Spiro compounds were characterized by 1H-NMR, FTIR, and Mass spectroscopy. The functionalized spiro-pyrrolizidines were found to be effective for biological uses by considering their in vitro screening and antimicrobial impacts. Spiro constituents were found to be much more effective for Gram-positive bacteria due to the stronger lipophilic character of the molecules, and they resulted feasible membrane permeation in a biological system. Based on the planarity geometry of the Spiro pyrrolizidines, meta-substitution possesses steric hindrance and hence shows less effectiveness compared to para-substitution on the same nucleus, which shows a marginal steric effect. The biological studies showed that the derived spiro heterocyclic systems have an inhibitory effect of 50%.

Estilos ABNT, Harvard, Vancouver, APA, etc.

30

DAY, R. O., K. C. K. SWAMY, L. FAIRCHILD, J. M. HOLMES e R. R. HOLMES. "ChemInform Abstract: Pentacoordinated Molecules. Part 85. Influence of Hydrogen Bonding on the Formation of Boat and Chair Conformations of Six-Membered Rings in Spirocyclic Tetraoxyphosphoranes." ChemInform 22, n.º 24 (23 de agosto de 2010): no. http://dx.doi.org/10.1002/chin.199124184.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

31

Yadav, J. S., B. V. Subba Reddy, V. Hari Krishna, T. Swamy e GG KS Narayana Kumar. "Iodine-promoted Prins-cyclization of ketones — A facile synthesis of spirocyclic-4-iodo-tetrahydropyrans and 5,6-dihydro-2H-pyrans". Canadian Journal of Chemistry 85, n.º 6 (1 de junho de 2007): 412–15. http://dx.doi.org/10.1139/v07-048.

Texto completo da fonte

Resumo:

Homoallylic and homopropargylic alcohols undergo smooth coupling with ketones in the presence of molecular iodine at ambient temperature to produce spirocyclic-4-iodotetrahydropyrans and 5,6-dihydro-2H-pyrans, respectively, in high yields in a short reaction time with high selectivity. The use of molecular iodine makes this procedure quite simple, more convenient, and cost-effective.Key words: Prins-cyclization, iodine, homopropargylic alcohol, spirocyclic-4-iodopyrans.

Estilos ABNT, Harvard, Vancouver, APA, etc.

32

Lukin, Alexei, Kristina Komarova, Lyubov Vinogradova, Elizaveta Rogacheva, Lyudmila Kraeva e Mikhail Krasavin. "Synthesis and Antibacterial Evaluation of Ciprofloxacin Congeners with Spirocyclic Amine Periphery". International Journal of Molecular Sciences 24, n.º 2 (4 de janeiro de 2023): 954. http://dx.doi.org/10.3390/ijms24020954.

Texto completo da fonte

Resumo:

The synthesis of novel fluoroquinolones, congeners of ciprofloxacin, which was inspired by earlier work on spirocyclic ciprofloxacin, is described. An antibacterial evaluation of the 11 fluoroquinolone compounds synthesized against the ESKAPE panel of pathogens in comparison with ciprofloxacin revealed that the more compact spirocycles in the fluoroquinolone periphery resulted in active compounds, while larger congeners gave compounds that displayed no activity at all. In the active cohort, the level of potency was comparable to that of ciprofloxacin. However, the spectrum of antibacterial activity was quite different, as the new compounds showed no activity against Pseudomonas aeruginosa. Among the prepared and tested compounds, the broadest range of activity (five pathogens of the six in the ESKAPE panel) and the highest level of activity were demonstrated by 1-yclopropyl-7-[8-(4-cyclopropyl-4H-1,2,4-triazol-3-yl)-6-azaspiro[3.4]oct-6-yl]-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid, which is the lead compound nominated for further characterization and development.

Estilos ABNT, Harvard, Vancouver, APA, etc.

33

Maassarani, Fida, Michel Pfeffer e Guy Le Borgne. "Reaction of cyclopalladated compounds Part 16. Stepwise insertion of one, two, and three alkyne molecules into the palladium-carbon bond of a six-membered palladocycle. One-pot synthesis of spirocyclic compounds". Organometallics 6, n.º 10 (outubro de 1987): 2043–53. http://dx.doi.org/10.1021/om00153a003.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

34

Kitschke, Philipp, Ana-Maria Preda, Alexander A. Auer, Sebastian Scholz, Tobias Rüffer, Heinrich Lang e Michael Mehring. "Spirocyclic tin salicyl alcoholates – a combined experimental and theoretical study on their structures, 119Sn NMR chemical shifts and reactivity in thermally induced twin polymerization". Dalton Transactions 48, n.º 1 (2019): 220–30. http://dx.doi.org/10.1039/c8dt03695k.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

35

Brindisi, Margherita, Sandra Gemma, Sanil Kunjir, Luisa Di Cerbo, Simone Brogi, Silvia Parapini, Sarah D'Alessandro et al. "Synthetic spirocyclic endoperoxides: new antimalarial scaffolds". MedChemComm 6, n.º 2 (2015): 357–62. http://dx.doi.org/10.1039/c4md00454j.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

36

Yuan, Hongdong, Chongrong Tang, Shikuan Su, Lei Cui, Xueshun Jia, Chunju Li e Jian Li. "A bicyclization reaction with two molecular allenyl ketones and isocyanides: synthesis of a lactone-containing azaspirocycle derivative". Chemical Communications 55, n.º 50 (2019): 7231–34. http://dx.doi.org/10.1039/c9cc02785h.

Texto completo da fonte

Resumo:

A novel bicyclization reaction of two molecular allenyl ketones and isocyanides has been disclosed. This strategy allows for the construction of structurally complex spirocyclic lactam–lactone systems in an efficient manner.

Estilos ABNT, Harvard, Vancouver, APA, etc.

37

Kour, Smit, Sandeep Rana, Smitha Kizhake, Dragana Lagundžin, David Klinkebiel, Jayapal Reddy Mallareddy, Tom Huxford, Nicholas T. Woods e Amarnath Natarajan. "Stapling proteins in the RELA complex inhibits TNFα-induced nuclear translocation of RELA". RSC Chemical Biology 3, n.º 1 (2022): 32–36. http://dx.doi.org/10.1039/d1cb00183c.

Texto completo da fonte

Resumo:

Discovery of a spirocyclic dimer (SpiD7) that covalently modifies RELA to generate stable high molecular weight complexes. SpiD7 inhibits TNFα-induced nuclear translocation of RELA resulting in the blockade of NF-kB gene transcription, through a previously unexplored modality.

Estilos ABNT, Harvard, Vancouver, APA, etc.

38

Biţă, Andrei, Ion Romulus Scorei, Nagendra Rangavajla, Ludovic Everard Bejenaru, Gabriela Rău, Cornelia Bejenaru, Maria Viorica Ciocîlteu et al. "Diester Chlorogenoborate Complex: A New Naturally Occurring Boron-Containing Compound". Inorganics 11, n.º 3 (9 de março de 2023): 112. http://dx.doi.org/10.3390/inorganics11030112.

Texto completo da fonte

Resumo:

The natural compounds of boron have many applications, primarily as a dietary supplement. The research is based on the discovery that the diester chlorogenoborate complex can be detected and quantified from green coffee beans. The study reports that such a diester molecule can also be synthesized in a stable form via the direct reaction of boric acid and chlorogenic acid in a mixture of acetonitrile–water (1:1, v/v) and left to evaporate over a period of 48 h at room temperature, resulting in a spirocyclic form (diester complex). The diester complex, with its molecular structure and digestibility attributes, has potential application as a prebiotic in gut health and oral health, and as a micronutrient essential for microbiota in humans and animals.

Estilos ABNT, Harvard, Vancouver, APA, etc.

39

Pesquet, Anthony, Hamid Marzag, Michael Knorr, Carsten Strohmann, Ata Martin Lawson, Alina Ghinet, Joëlle Dubois, Farce Amaury, Adam Daïch e Mohamed Othman. "Access to 3-spiroindolizines containing an isoindole ring through intra-molecular arylation of spiro-N-acyliminium species: a new family of potent farnesyltransferase inhibitors". Organic & Biomolecular Chemistry 17, n.º 10 (2019): 2798–808. http://dx.doi.org/10.1039/c8ob02612b.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

40

Song, Kunpeng, Yinjie Wang, Fang Ruan, Weiwei Yang e Jiping Liu. "Synthesis of a Novel Spirocyclic Inflatable Flame Retardant and Its Application in Epoxy Composites". Polymers 12, n.º 11 (29 de outubro de 2020): 2534. http://dx.doi.org/10.3390/polym12112534.

Texto completo da fonte

Resumo:

Derivatives of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5,5]undecane-3,9-dioxide (SPDPC) are of increasing interest as flame retardants for polymeric materials. In addition, SPDPC is also an important intermediate for the preparation of intumescent flame retardants (IFRs). However, low efficiency and undesirable dispersion are two major problems that seriously restrain the application of IFRs as appropriate flame retardants for polymer materials. Usually, the functionalization or modification of SPDPC is crucial to acquiring high-performance polymer composites. Here, a small molecule spirocyclic flame retardant diphenylimidazole spirocyclic pentaerythritol bisphosphonate (PIPC) was successfully prepared through the substitution reaction between previously synthesized intermediate SPDPC and 2-phenylimidazole (PIM). Phenyl group and imidazole group were uniformly anchored on the molecular structure of SPDPC. This kind of more uniform distribution of flame retardant groups within the epoxy matrix resulted in a synergistic flame retardant effect and enhanced the strength of char layers to the epoxy composites, when compared to the unmodified epoxy. The sample reached a limiting oxygen index (LOI) of 29.7% and passed with a V-0 rating in the UL 94 test with the incorporation of only 5 wt% of as-prepared flame retardant PIPC. Moreover, its peak of heat release rate (pHRR) and total heat release (THR) decreased by 41.15% and 21.64% in a cone calorimeter test, respectively. Furthermore, the addition of PIPC has only slightly impacted the mechanical properties of epoxy composites with a low loading.

Estilos ABNT, Harvard, Vancouver, APA, etc.

41

Kotha, Sambasivarao, e Kalyaneswar Mandal. "Metathetic approach to naphthoxepin and spirocyclic molecular frameworks". Tetrahedron Letters 45, n.º 7 (fevereiro de 2004): 1391–94. http://dx.doi.org/10.1016/j.tetlet.2003.12.075.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

42

Sawhney, Gifty, Javeed Ur Rasool, Diksha Saroch, Mumin Ozturk, Frank Brombacher, Bilal Ahmad, Asha Bhagat, Asif Ali, Suraj P. Parihar e Zabeer Ahmed. "Arteannuin-B and (3-Chlorophenyl)-2-Spiroisoxazoline Derivative Exhibit Anti-Inflammatory Effects in LPS-Activated RAW 264.7 Macrophages and BALB/c Mice-Induced Proinflammatory Responses via Downregulation of NF-κB/P38 MAPK Signaling". Molecules 27, n.º 22 (20 de novembro de 2022): 8068. http://dx.doi.org/10.3390/molecules27228068.

Texto completo da fonte

Resumo:

Host inflammatory responses are key to protection against injury; however, persistent inflammation is detrimental and contributes to morbidity and mortality. Herein, we demonstrated the anti-inflammatory role of Arteannuin-B (1) and its new spirocyclic-2-isoxazoline derivative JR-9 and their side effects in acute inflammatory condition in vivo using LPS-induced cytokines assay, carrageenan-induced paw edema, acetic acid-induced writhing and tail immersion. The results show that the spirocyclic-2-isoxazoline derivative is a potent anti-inflammatory agent with minimal cell toxicity as compared to Arteannuin-B. In addition, the efficacies of these compounds were also validated by flow cytometric, computational, and histopathological analysis. Our results show that the anti-inflammatory response of JR-9 significantly reduces the ability of mouse macrophages to produce NO, TNF-α, and IL-6 following LPS stimulation. Therefore, JR-9 is a prospective candidate for the development of anti-inflammatory drugs and its molecular mechanism is likely related to the regulation of NF-κB and MAPK signaling pathway.

Estilos ABNT, Harvard, Vancouver, APA, etc.

43

Khuzin, Artur A., Dim I. Galimov e Liliya L. Khuzina. "Photochromic and Luminescent Properties of a Salt of a Hybrid Molecule Based on C60 Fullerene and Spiropyran—A Promising Approach to the Creation of Anticancer Drugs". Molecules 28, n.º 3 (22 de janeiro de 2023): 1107. http://dx.doi.org/10.3390/molecules28031107.

Texto completo da fonte

Resumo:

For the first time a pyrrolidinofullerene salt containing a spiropyran group and an ammonium group, capable of reversibly reacting to UV radiation, has been synthesized. Photoinduced reactions of the synthesized compounds were studied using absorption and luminescence spectroscopies, spectral and kinetic characteristics were measured. The hybrid molecule was found to exhibit intrinsic fluorescence even in the spirocyclic form. The С60 derivative showed a higher stability and better spectral and luminescent properties than the precursor.

Estilos ABNT, Harvard, Vancouver, APA, etc.

44

Qu, Haijun, Xuejian Li, Fan Mo e Xufeng Lin. "Efficient synthesis of dihydropyrimidinones via a three-component Biginelli-type reaction of urea, alkylaldehyde and arylaldehyde". Beilstein Journal of Organic Chemistry 9 (11 de dezembro de 2013): 2846–51. http://dx.doi.org/10.3762/bjoc.9.320.

Texto completo da fonte

Resumo:

A one-pot three-component synthesis of dihydropyrimidinones via a molecular iodine-catalyzed tandem reaction of simple readily available mono-substituted urea, alkylaldehyde, and arylaldehyde has been developed. The reaction proceeds with high chemo- and regioselectivity to give highly diverse dihydropyrimidinones in reasonable yields under mild reaction conditions. Moreover, the first catalytic enantioselective version of this reaction was also realized by using chiral spirocyclic SPINOL-phosphoric acids.

Estilos ABNT, Harvard, Vancouver, APA, etc.

45

Maddirala, Amarendar Reddy, e Peter R. Andreana. "Methyl isocyanide as a convertible functional group for the synthesis of spirocyclic oxindole γ-lactams via post-Ugi-4CR/transamidation/cyclization in a one-pot, three-step sequence". Beilstein Journal of Organic Chemistry 14 (18 de abril de 2018): 875–83. http://dx.doi.org/10.3762/bjoc.14.74.

Texto completo da fonte

Resumo:

The synthesis of spiro[indoline-3,2'-pyrrole]-2,5'(1'H)-diones and spiro[indoline-3,2'-pyrrolidine]-2,5'-diones, via a post-Ugi-domino transamidation/cyclization sequential process, has been achieved in three sequential steps utilizing a one-pot reaction protocol. The variation in carboxylic acid substrates allows for the generation of new chiral racemic quaternary carbon centers under basic conditions providing molecular diversity and a small library of spirocyclic oxindoles.

Estilos ABNT, Harvard, Vancouver, APA, etc.

46

Böhm, Stanislav, Michal Hocek, Jan Němeček, Vladimír Havlíček e Josef Kuthan. "Preparation and Spectroscopic Properties of Spirocyclic 1-Methyl-2,4,4,6-tetraaryl-1,4-dihydropyridines". Collection of Czechoslovak Chemical Communications 59, n.º 5 (1994): 1105–14. http://dx.doi.org/10.1135/cccc19941105.

Texto completo da fonte

Resumo:

1,5-Diones Ib - Ie were converted to spirocyclic 1,4-dihydropyridines IIb - IIe by treatment with methanolic methylamine. The starting diketones Ib - Ie were obtained from corresponding acetophenones 4-X-C6H4COMe and fluorenone with sodium amide except of If where only ketone III and 1,4-dione IV were isolated. Molecular spectra (UV-VIS, NMR, IR and MS) of compounds Ib - Ie, IIa - IIe, III, and IV were assigned and interpreted.

Estilos ABNT, Harvard, Vancouver, APA, etc.

47

Lukyanov, Boris, Gennadii Vasilyuk, Eugene Mukhanov, Leonid Ageev, Maria Lukyanova, Yury Alexeenko, Serguei Besugliy e Valeri Tkachev. "Multifunctional Spirocyclic Systems". International Journal of Photoenergy 2009 (2009): 1–6. http://dx.doi.org/10.1155/2009/689450.

Texto completo da fonte

Resumo:

New spiropyrans with different substituents in the benzopyran fragment have been synthesized and investigated. It was shown that introduction of aldehyde group in the structure of spiropyrans gives a possibility to obtain new functionalized compounds. Effects of the substituents on the photochromic behavior were studied.

Estilos ABNT, Harvard, Vancouver, APA, etc.

48

Shetgaonkar, Samata E., Shiva Prasad Kollur, Renjith Raveendran Pillai, Karthick Thangavel, Sanja J. Armaković, Stevan Armaković, Chandan Shivamallu et al. "Investigation of Pharmaceutical Importance of 2H-Pyran-2-One Analogues via Computational Approaches". Symmetry 13, n.º 9 (3 de setembro de 2021): 1619. http://dx.doi.org/10.3390/sym13091619.

Texto completo da fonte

Resumo:

Highly functionalized spirocyclic ketals were synthesized through asymmetric oxidative spirocyclization via carbanion-induced ring transformation of 2H-pyran-2-ones with 1,4-cyclohexandione monoethyleneketal under alkaline conditions. Further acidic-hydrolysis of obtained spirocyclic ketals yields highly substituted 2-tetralone in good yield. Computational analysis based on the DFT calculations and MD simulations has been performed in order to predict and understand global and local reactivity properties of newly synthesized derivatives. DFT calculations covered fundamental reactivity descriptors such as molecular electrostatic potential and average local ionization energies. Nitrogen atom and benzene rings have been recognized as the most important molecular sites from these aspects. Additionally, to predict whether studied compounds are stable towards the autoxidation mechanism, we have also studied the bond dissociation energies for hydrogen abstraction and identified the derivative which might form potentially genotoxic impurities. Interactions with water, including both global and local aspects, have been covered thanks to the MD simulations and calculations of interaction energies with water, counting of formed hydrogen interactions, and radial distribution functions. MD simulations were also used to identify which excipient could be used together with these compounds, and it has been established that the polyvinylpyrrolidone polymer could be highly compatible with these compounds, from the aspect of calculated solubility parameters.

Estilos ABNT, Harvard, Vancouver, APA, etc.

49

Garcia-Yuste, Santiago, Konrad W. Hellmann, Lutz H. Gade, Ian J. Scowen e Mary McPartlin. "Bis[1,3-bis(diphenylmethylsilylamido)propane]zirconium: A Spirocyclic Complex Containing a Sterically Demanding Chelating Amido Ligand". Zeitschrift für Naturforschung B 54, n.º 10 (1 de outubro de 1999): 1260–64. http://dx.doi.org/10.1515/znb-1999-1007.

Texto completo da fonte

Resumo:

Lithiation of the diamine CH2(CH2NHSiMePh2)2 using n-butyl lithium and subsequent reaction with zirconium tetrachloride yielded the bis(chelate)-amidozirconium complex [Zr{CH2(CH2NSiMePh2)2}2]- The spirocyclic molecule has a distorted tetrahedral coordination at the zirconium centre with overall C2 symmetry broken only by the relative orientation of four phenyl rings. The bulky diphenylmethylsilyl substituents at the amido-N functions as well as the ligand backbone sterically protect the metal centre and render it inert towards conproportionation with zirconium chloride.

Estilos ABNT, Harvard, Vancouver, APA, etc.

50

Livendahl, M., J. Jamroskovic, M. Hedenström, T. Görlich, N. Sabouri e E. Chorell. "Synthesis of phenanthridine spiropyrans and studies of their effects on G-quadruplex DNA". Organic & Biomolecular Chemistry 15, n.º 15 (2017): 3265–75. http://dx.doi.org/10.1039/c7ob00300e.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Oferecemos descontos em todos os planos premium para autores cujas obras estão incluídas em seleções literárias temáticas. Contate-nos para obter um código promocional único!