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.
Catalytic asymmetric reductive amination of ketones via highly enantioselective hydrogenation of the CN double bond
作者:Mark J. Burk、Jose P. Martinez、John E. Feaster、Nick Cosford
DOI:10.1016/s0040-4020(01)89375-3
日期:1994.4
a convenient, chemoselective asymmetric reductive amination procedure for the conversion of ketones to chiral hydrazines and amines. The key step in the three-step process is enantioselective DuPHOS-Rh-catalyzed hydrogenation of the CN double bond of N-acylhydrazones. Detailed optimization studies revealed the effect of solvent, temperature, and the N-acyl group on the enantioselectivity and catalytic
Nickel-Catalyzed Asymmetric Transfer Hydrogenation of Hydrazones and Other Ketimines
作者:Haiyan Xu、Peng Yang、Pratanphorn Chuanprasit、Hajime Hirao、Jianrong Steve Zhou
DOI:10.1002/anie.201501018
日期:2015.4.20
We report the use of nickel catalysts for the catalytic transferhydrogenation of hydrazones and otherketimines with formic acid. Strongly donating bisphosphines must be used to support the catalysts. As in enzymatic catalysis, attractive weak interactions may be important for stereochemical control by the nickel/binapine catalyst.