Asymmetric organocatalytic reduction of ketimines with catecholborane employing a N-triflyl phosphoramide Brønsted acid as catalyst
作者:Dieter Enders、Andreas Rembiak、Matthias Seppelt
DOI:10.1016/j.tetlet.2012.11.055
日期:2013.2
The first asymmetric reduction of ketimines with catecholborane employing an enantiopure N-triflyl phosphoramide as the organocatalyst has been developed. Five mole % of the catalyst provides the corresponding secondary amines in very good to almost quantitative yields and good enantioselectivities up to 86:14 e.r. under mild reaction conditions.
<scp>l</scp>-Valine derived chiral N-sulfinamides as effective organocatalysts for the asymmetric hydrosilylation of N-alkyl and N-aryl protected ketimines
作者:Chao Wang、Xinjun Wu、Li Zhou、Jian Sun
DOI:10.1039/c4ob01257g
日期:——
L-Valine derived N-sulfinamides have been developed as efficient enantioselective Lewis basic organocatalysts for the asymmetric reduction of N-aryl and N-alkyl ketimines with trichlorosilane. Catalyst 3c afforded up to 99% yield and 96% ee in the reduction of N-alkyl ketimines and up to 98% yield and 98% ee in the reduction of N-aryl ketimines.