Ruthenium-Catalyzed Enantioselective Hydrogenation of Hydrazones
作者:Christopher H. Schuster、James F. Dropinski、Michael Shevlin、Hongming Li、Song Chen
DOI:10.1021/acs.orglett.0c02756
日期:2020.10.2
Prochiral hydrazones undergo efficient and highly selective hydrogenation in the presence of a chiral diphosphine ruthenium catalyst, yielding enantioenriched hydrazine products (up to 99% ee). The mild reaction conditions and broad functional group tolerance of this method allow access to versatile chiral hydrazine building blocks containing aryl bromide, heteroaryl, alkyl, cycloalkyl, and ester substituents
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).