Orthoacylimines: A New Class of Chiral Auxiliaries for Nucleophilic Addition of Organolithium Reagents to Imines
作者:Alessandro A. Boezio、Geoffrey Solberghe、Caroline Lauzon、André B. Charette
DOI:10.1021/jo026571m
日期:2003.4.1
orthoacylimine-derived chiral auxiliaries has been synthesized and tested in the nucleophilicaddition of organolithium reagents to imines. The precursors can be prepared by an aza-Wittig reaction between the corresponding orthoacyl azide and a variety of aldehydes in the presence of trialkylphosphines. The nucleophilicaddition of organolithium reagents led to the addition products in good yields
Rhodium-Catalyzed Asymmetric Hydrogenation of Unprotected NH Imines Assisted by a Thiourea
作者:Qingyang Zhao、Jialin Wen、Renchang Tan、Kexuan Huang、Pedro Metola、Rui Wang、Eric V. Anslyn、Xumu Zhang
DOI:10.1002/anie.201404570
日期:2014.8.4
Asymmetrichydrogenation of unprotected NH imines catalyzed by rhodium/bis(phosphine)‐thiourea provided chiral amines with up to 97 % yield and 95 % ee. 1H NMR studies, coupled with control experiments, implied that catalytic chloride‐bound intermediates were involved in the mechanism through a dual hydrogen‐bonding interaction. Deuteration experiments proved that the hydrogenation proceeded through
由铑/双(膦)-硫脲催化的未保护的NH亚胺的不对称氢化提供了手性胺,产率高达97%,ee值高达95% 。1 H NMR 研究与对照实验相结合,表明催化氯化物结合中间体通过双氢键相互作用参与了该机制。氘化实验证明氢化反应是通过与亚胺一致的途径进行的。
Chiral quaternary benzophenone hydrazonium salt derivatives; Efficient chiral catalysts for the enantioselective phase-transfer alkylation of imines. Application to synthesis of chiral primary amines
作者:J.Jamal Eddine、M. Cherqaoui
DOI:10.1016/0957-4166(95)00149-j
日期:1995.6
(2S)-1-Methyl-1-[N-(diphenylmethylene)]-2-hydroxymethylpyrrolidine hydrazonium iodide I-a has been designed to catalyse the enantioselective phase-transfer alkylation of N-(diphenylmethylene) benzenemethanamine II. Although the weak acidic character of the latter, alkylations have been performed within reasonable reaction times. Optically active Primary amines III a-e have been prepared in good chemical yields and up to 94% e.e. using 2-5 mol-% of the chiral catalyst only.
作者:Guohua Hou、Francis Gosselin、Wei Li、J. Christopher McWilliams、Yongkui Sun、Mark Weisel、Paul D. O’Shea、Cheng-yi Chen、Ian W. Davies、Xumu Zhang
DOI:10.1021/ja903319r
日期:2009.7.29
N-H ketoimines 3a-3v are readily prepared in high yield via organometallic addition to nitrites and isolated as corresponding bench-stable hydrochloride salts. Homogeneous asymmetric hydrogenation of unprotected N-H ketoimines 3a-3v using Ir-(S,S)-f binaphane as catalyst provides chiral amines 4a-4v in 90-95% yield with enantioselectivities up to 95% ee.