Disulfonimide‐Catalyzed Asymmetric Reduction of
<i>N</i>
‐Alkyl Imines
作者:Vijay N. Wakchaure、Philip S. J. Kaib、Markus Leutzsch、Benjamin List
DOI:10.1002/anie.201504052
日期:2015.9.28
A chiral disulfonimide (DSI)‐catalyzedasymmetric reduction of N‐alkyl imines with Hantzsch esters as a hydrogen source in the presence of Boc2O has been developed. The reaction delivers Boc‐protectedN‐alkyl amines with excellent yields and enantioselectivity. The method tolerates a large variety of alkyl amines, thus illustrating potential for a general reductive cross‐coupling of ketones with diverse
A process for the catalytic hydrogenation or asymmetric hydrogenation of imines of Formula (I) to the corresponding amines of Formula (II) is provided in which R
1
is aryl; R
2
is aryl, cyclic, alkyl, alkenyl or alkynyl; and R
3
is alkyl. The catalytic system includes a ruthenium complex containing (1) a diamine and (2) a diphosphine or two monodentate phosphines ligands. Such process also relates to the asymmetric hydrogenation of prochiral imines to the chiral amines using chiral ruthenium complexes bearing chiral diphosphines or chiral monodentate phosphines and chiral diamines.