Asymmetric Hydrogenation of N-Alkyl Ketimines with Phosphine-Free, Chiral, Cationic Ru-MsDPEN Catalysts
作者:Fei Chen、Tianli Wang、Yanmei He、Ziyuan Ding、Zhiwei Li、Lijin Xu、Qing-Hua Fan
DOI:10.1002/chem.201002846
日期:2011.1.24
(Solvent) free and easy: A phosphine‐free, chiral, cationicRu–MsDPEN complex [(S,S)‐1] is found to be an efficient catalyst for the enantioselective hydrogenation of a range of often‐problematic N‐alkyl ketimines (see scheme). This new method provides a more practical and greener synthetic approach to optically active amines, particularly N‐alkyl amines, such as Sertraline.
A Tandem Conjugate Addition/Cyclization Protocol for the Asymmetric Synthesis of 2-Aryl-4-aminotetrahydroquinoline-3-carboxylic Acid Derivatives
作者:Stephen G. Davies、Nadeam Mujtaba、Paul M. Roberts、Andrew D. Smith、James E. Thomson
DOI:10.1021/ol9004118
日期:2009.5.7
Condensation of tert-butyl (E)-3-(2′-aminophenyl)propenoate with a range of aromatic and heteroaromatic aldehydes gives the corresponding imines as single diastereoisomers (>98% de). Addition of lithium (R)-N-benzyl-N-(α-methylbenzyl)amide initiates a tandem conjugate addition/cyclization reaction to generate 2-aryl-4-aminotetrahydroquinoline-3-carboxylic acid derivatives in >98% de, >98% ee and high isolated