Effect of Aryl Ring Fluorination on the Antibacterial Properties of C4 Aryl-Substituted N-Methylthio β-Lactams
摘要:
4-Aryl-substituted N-thiolated beta-lactams are a new family of antibacterial agents possessing unique structure activity profiles and a mode of action. Unlike traditional beta-lactam antibiotics, which require highly polar enzyme-binding groups, these lactams bear hydrophobic groups on their side chains. In this study, we examine the effect that increasing hydrophobicity, through fluorine substitution in the C-4 aryl ring, has on the antibacterial properties. (C) 2003 Elsevier Science Ltd. All rights reserved.
Ruthenium-catalyzed double-fold C–H tertiary alkoxycarbonylation of arenes using di-tert-butyl dicarbonate
作者:Xiaohu Hong、Hao Wang、Bingxin Liu、Bin Xu
DOI:10.1039/c4cc05173d
日期:——
An efficient ruthenium-catalyzed double-fold C–H bond alkoxycarbonylation of arenes was developed using commercially available Boc2O as the tertiary esterification reagent.
Aldimine-Directed Branched-Selective Hydroarylation of Styrenes
作者:Pin-Sheng Lee、Naohiko Yoshikai
DOI:10.1002/anie.201207958
日期:2013.1.21
Branching out: A simple and inexpensive cobalt/triarylphosphine catalyst promotes aldimine‐directed hydroarylation of styrene with high branched regioselectivity to afford 1,1‐diarylethane derivatives in good yields under mild reaction conditions. The ortho‐formyl group in the hydroarylation products is amenable to dehydrative cyclization, to give fused polycyclic aromatic hydrocarbons, as well as
Asymmetric synthesis of α-arylglycinols via additions of lithium methyl p-tolyl sulfoxide to N-(PMP)arylaldimines followed by “non oxidative” Pummerer reaction
作者:Pierfrancesco Bravo、Silvia Capelli、Marcello Crucianelli、Maurizia Guidetti、Andrey L Markovsky、Stefano V Meille、Vadim A Soloshonok、Alexander E Sorochinsky、Fiorenza Viani、Matteo Zanda
DOI:10.1016/s0040-4020(99)00064-2
日期:1999.3
favor the opposite stereochemical outcome. On the other hand, the reactions run under thermodynamically controlled conditions (0 °C) afforded equimolar mixtures of the diastereomeric products regardless of the pattern of substitution on the starting imines. Enantiopure α-arylglycinols were readily synthesized by “non-oxidative” Pummerer rearrangement of diastereomerically pure β-aryl-β-N-(acyl)aminoalkyl
Lipase-catalyzed resolution of 4-aryl-substituted β-lactams: effect of substitution on the 4-aryl ring
作者:Jason A Carr、Talal F Al-Azemi、Timothy E Long、Jeung-Yeop Shim、Cristina M Coates、Edward Turos、Kirpal S Bisht
DOI:10.1016/j.tet.2003.09.057
日期:2003.11
reactions occurred with high enantioselectivity and substrate conversion. The effect of substitution on the C-4 aryl ring on lipase hydrolytic activity was dependent upon the steric and electronic nature of the substituent and its position on the aryl ring. The stereopreference of the lipase PS-30 for the (3S,4R) enantiomer was rationalized using a known active site model. Absolute stereochemistry of the
Quinone-catalyzed oxidative deformylation: synthesis of imines from amino alcohols
作者:Xinyun Liu、Johnny H Phan、Benjamin J Haugeberg、Shrikant S Londhe、Michael D Clift
DOI:10.3762/bjoc.13.282
日期:——
A new method for imine synthesis by way of quinone-catalyzed oxidative deformylation of 1,2-amino alcohols is reported. A wide range of readily accessible amino alcohols and primary amines can be reacted to provide N-protected imine products. The methodology presented provides a novel organocatalytic approach for imine synthesis and demonstrates the synthetic versatility of quinone-catalyzed oxidative