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Bicyclic molecule

About: Bicyclic molecule is a research topic. Over the lifetime, 29587 publications have been published within this topic receiving 451252 citations. The topic is also known as: bicyclic molecule.


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Journal ArticleDOI
TL;DR: A prototype carbamate 12a was studied further and found to meet several significant in vitro microbiological criteria required for a novel anti-H.
Abstract: 2-[[(2-Pyridyl)methyl]thio]-1H-benzimidazoles (2, sulfides) exhibit antibacterial properties that are selective for Helicobacter spp., but they also have an inherent susceptibility to metabolic oxidation to furnish 2-[[(2-pyridyl)methyl]sulfinyl]-1H-benzimidazoles (1), which act as proton pump inhibitors (PPIs). We have discovered five compounds with retained antibacterial potency and selectivity in which the overall framework of the sulfides 2 could be kept intact while structural modifications were made to remove PPI activity. These compounds, 2-[((2-methyl-3-(2-(2-(2-methoxyethoxy)ethoxy)ethylthio)phenyl)methyl)thio]-1H-benzimidazole (79), 2-[((2-methyl-3-(2-(2-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)ethoxy)ethylthio)phenyl)methyl)thio]-1H-benzimidazole (80), 2-[((2-methyl-3-((2-morpholino)ethylthio)phenyl)methyl)thio]-1H-benzimidazole (86), 2-[[[2-methyl-3-[2-(2-methyl-5-nitroimidazol-1-yl)ethylthio]phenyl]methyl]thio]-1H-benzimidazole (88), and 2-[[[2-methyl-3-[2-(1,2,4-triazol-1-yl)ethylthio]phenyl]methyl]thio]-1H-benzimidazole (89), had minimum bactericidal concentrations (MBCs) of 0.5, 0.5, 1, 2, and 4 microg/mL, respectively. The reported compounds are bactericidal with MBCs within 1 order of magnitude of MBCs of clinically used antimicrobials such as clarithromycin (0.1 microg/mL) or metronidazole (2-4 microg/mL) but differ from these inasmuch that they have an extremely narrow spectrum activity and appear to be species specific.

84 citations

Journal ArticleDOI
TL;DR: In this paper, a kinetic and mechanistic study of arene hydrogenation by supported organoactinide complexes is presented, showing that benzene is preferentially hydrogenated with almost complete exclusion of p-xylene (approximately]97:3), inferring that the benzene binding constant to the active sites is [approximately]6.7[times] that of pxylene.
Abstract: This contribution reports a kinetic and mechanistic study of arene hydrogenation by the supported organoactinide complexes Cp[prime]Th(benzyl)[sub 3]/DA (1/DA), Th(1,3,5-CH[sub 2]C[sub 6]H[sub 3]Me[sub 2])[sub 4]/DA (2/DA), and Th([eta][sup 3]-allyl)[sub 4]/DA (3/DA) where Cp[prime] = [eta][sup 5]-Me[sub 5]C[sub 5] and DA = dehydroxylated [gamma]-alumina. In slurry reactions (90[degrees]C, P[sub H[sub 2]] = 180 psi), the activity for benzene hydrogenation follows the order 1/DA toluene > p-xylene > naphthalene, with the regiochemistry of p-xylene reduction similar to that for benzene. Experiments with 1:1 benzene-p-xylene mixtures reveal that benzene is preferentially hydrogenated with almost complete exclusion of p-xylene ([approximately]97:3), inferring that the benzene binding constant to the active sites is [approximately]6.7[times] that of p-xylene. 51 refs., 8 figs., 2 tabs.« less

84 citations

Journal ArticleDOI
TL;DR: Optically active bicyclic β-lactam, 7-(oxazolidin-3-yl)-5-oxa-1-azabicyclo[4.2.0]octan-8-one (5a-c) was synthesized by photolysis of optically active oxazolidine carbene chromium complex with oxazine.
Abstract: Optically active bicyclic β-lactam, 7-(oxazolidin-3-yl)-5-oxa-1-azabicyclo[4.2.0]octan-8-one (3), was synthesized by photolysis of optically active oxazolidine carbene chromium complex (1) with oxazine (2). Conversion of the oxazolidine to the oxazolidinone gave a bicyclic β-lactam readily α-alkylated, 7-alkyl-7-(2-oxooxazolidin-3-yl)-5-oxa-1-azabicyclo[4.2.0]octan-8-one (5a-c). Cleavage of tha alkylated β-lactam gave optically active ester aldehyde, 2-formyl-2-(2-oxooxazolidin-3-yl)propanoate (7), which was converted to a number of optically active α-alkyl-α-aminoacids. These include (R)-α-methylserine, (S)-α-methylglutamic acid, (S)-α-methylornithine, (S)-vinylalanine, (S)-ethynylalanine, and (S)-2-methyl-2,3-diaminopropionic acid

84 citations

Journal ArticleDOI
TL;DR: New C2-symmetric bicyclo[2.2.1]hepta-2,5-dienes bearing methyl and phenyl substituents at the 2 and 5 positions were prepared enantiomerically pure through a two-step sequence starting from the readily available bicyclo(diene)2-dione due to the instability or volatility of these dienes.
Abstract: New C2-symmetric bicyclo[2.2.1]hepta-2,5-dienes bearing methyl and phenyl substituents at the 2 and 5 positions were prepared enantiomerically pure through a two-step sequence starting from the readily available bicyclo[2.2.1]hepta-2,5-dione. Due to the instability or volatility of these dienes, their isolation was achieved through the formation of the corresponding stable [RhCl(diene)]2 complexes. These chiral rhodium complexes displayed high activity and enantioselectivity (up to 99% ee) in the rhodium-catalyzed 1,4-addition and 1,2-addition of phenylboronic acid to cyclic enones and N-sulfonylimines, respectively.

84 citations

Journal ArticleDOI
TL;DR: The results and those obtained from reaction of 1 with 9-EtGH suggest that the platinum compound binds the N7 atoms of two guanines of the same strand, forming intrastrand cross-linked adducts.
Abstract: The formation and isolation of the antitumor drug cisplatin analogue cis-[PtCl2(Hmtpo-N3)2]·2H2O (1) (where Hmtpo = 4,7-H-5-methyl-7-oxo[1,2,4]triazolo[1,5-a]pyrimidine) by reaction of Hmtpo with K2[PtCl4] in HCl (0.5 N) is reported. This complex crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 15.215(2) A, b = 9.629(1) A, c = 13.115(3) A, β = 97.40(2)°, and Z = 4. The molecular structure shows that Pt is in an almost square planar environment, PtN2Cl2, which has a cis configuration. The Hmtpo ligands show a head to head orientation in the solid state and nonrestricted rotation about the Pt−N bonds in solution. The reactivity of the complex to model nucleobases 9-ethylguanine (9-EtGH) and 1-methylcytosine (1-MeC) has been investigated by 1H NMR spectroscopy at 45 °C in aqueous media. The results show that 1 reacts slowly with 9-EtGH (t1/2 ≈ 5 days) by displacement of Cl-, producing cis-[Pt(mtpo-N3)2(9-EtGH-N7)2], which is similar to the major cross-link adduct of cisplatin wi...

83 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023206
2022476
2021237
2020259
2019304
2018283