Ring Opening of Donor-Acceptor Cyclopropanes with the Azide Ion: A Tool for Construction of N-Heterocycles
作者:Konstantin L. Ivanov、Elena V. Villemson、Ekaterina M. Budynina、Olga A. Ivanova、Igor V. Trushkov、Mikhail Ya. Melnikov
DOI:10.1002/chem.201405551
日期:2015.3.23
general method for ringopening of various donor–acceptor cyclopropanes with the azide ion through an SN2‐like reaction has been developed. This highly regioselective and stereospecific process proceeds through nucleophilic attack on the more‐substituted C2 atom of a cyclopropane with complete inversion of configuration at this center. Results of DFT calculations support the SN2 mechanism and demonstrate
已经开发出一种通用的方法,可通过类似S N 2的反应,将叠氮离子与各种供体-受体环丙烷开环。这种高度区域选择性和立体选择性的过程是通过亲核攻击环丙烷的更取代的C2原子进行的,该中心的构型完全反转。DFT计算结果支持S N2机理,证明环丙烷的相对实验反应性与计算出的能垒之间具有良好的定性相关性。该反应为多种多官能叠氮化物提供了一种简单的方法,产率高达91%。这些叠氮化物具有很高的合成效用,并参与了面向多样性的合成,这是通过已开发的将其转变为五元,六元和七元N杂环以及复杂的环状化合物的多径策略证明的。包括天然产物和药物,如(-)-尼古丁和阿托伐他汀。
Antibacterial agents
申请人:Ellsworth Lee Edmund
公开号:US20050096278A1
公开(公告)日:2005-05-05
Compounds of formula I, II, III, IV, IV, and VI and methods for their preparation are disclosed. Further disclosed are methods of making biologically active compounds of formula I as well as pharmaceutically acceptable compositions comprising compounds of formula I. Compounds of formula I as disclosed herein can be used in a variety of applications including use as antibacterial agents.
Microbiological Transformations. 47. A Step toward a Green Chemistry Preparation of Enantiopure (<i>S</i>)-2-, -3-, and -4-Pyridyloxirane via an Epoxide Hydrolase Catalyzed Kinetic Resolution
作者:Yvonne Genzel、Alain Archelas、Q. B. Broxterman、Birgit Schulze、Roland Furstoss
DOI:10.1021/jo001406x
日期:2001.1.1
The biocatalyzed hydrolytic kinetic resolution of 2-, 3-, and 4-pyridyloxirane by the Aspergillus niger epoxide hydrolase (EH) has been explored. This was used to perform a gram scale preparation of these epoxides of (S) absolute configuration using a process performed at a concentration as high as 10 g/L (82 mM). All three epoxides have been obtained in a nearly enantiopure form (ee > 98%). Interestingly, it was shown that this biotransformation could be achieved using plain water instead of buffer solution, an important improvement as far as downstream processing of an eventual industrial process is concerned. Neither of these substrates could be obtained in reasonable enantiomeric purity and yield using the nowadays most efficient metal-based catalysts.
US5196433A
申请人:——
公开号:US5196433A
公开(公告)日:1993-03-23
[EN] QUINOLONE ANTIBACTERIAL AGENTS<br/>[FR] AGENTS ANTIBACTERIENS A BASE DE QUINOLONE