Nickel-Catalyzed N-Alkylation of Acylhydrazines and Arylamines Using Alcohols and Enantioselective Examples
作者:Peng Yang、Caili Zhang、Yu Ma、Caiyun Zhang、Aijie Li、Bo Tang、Jianrong Steve Zhou
DOI:10.1002/anie.201708949
日期:2017.11.13
atom‐economic way to prepare alkylamines, ideally with water as the sole byproduct. Herein, nickel catalysts are used for direct N‐alkylation of hydrazides and arylamines using racemic alcohols. Moreover, a nickel catalyst of (S)‐binapine was used for an asymmetric N‐alkylation of benzohydrazide with racemic benzylic alcohols.
An asymmetrichydrogenation of hydrazones with a unique nickel catalyst has been developed for the synthesis of chiral hydrazines with up to 99 % yield and 99.4 : 0.6 er and a broad substrate scope. Deuterium labelling experiments indicated that the hydrazone substrates undergo imine-enamine tautomerization in the mixed solvents.
Enantioselective hydrogenation of the C:N group: a catalytic asymmetric reductive amination procedure
作者:Mark J. Burk、John E. Feaster
DOI:10.1021/ja00041a067
日期:1992.7
substituents on phosphorus-linked aryl groups dramatically enhance the enantioselectivity. Such electronic effects of ligands on the enantioselectivity are rare, and as in the welldocumented case of Mn(II1)-mediated epoxidation reactions,' these may play an important role in the design of new catalysts. The highest enantioselectivities are obtained in nonpolar solvents (C6F6 = hexane > benzene > THF),
An efficient cobalt-catalyzed asymmetric reductive amination of ketones with hydrazides has been realized, directly producing valuable chiral hydrazines in high yields and enantioselectivities (up to 98% enantiomeric excess).