Development of highly enantioselective new Lewis basic N-formamide organocatalysts for hydrosilylation of imines with an unprecedented substrate profile
作者:Pengcheng Wu、Zhouyu Wang、Mounuo Cheng、Li Zhou、Jian Sun
DOI:10.1016/j.tet.2008.09.034
日期:2008.12
ketimines and non-methyl ketimines were catalyzed to afford the desired amines in good to high yield and enantioselectivity. In particular, catalyst 6e enabled the reduction of the difficult bulky ketimines to be highly efficient and enantioselective, affording up to 99% yield and 97% ee. This catalyst proved to prefer the relatively bulkier non-methyl acyclic ketimines to the methyl ketimines as substrate
已经开发了由1-哌啉酸衍生的N-甲酰胺作为新的路易斯碱性有机催化剂,其使用三氯硅烷作为还原剂来促进N-芳基酮亚胺的不对称还原。哌嗪基主链的N 4上的取代基和2-羧酰胺基均被证明对催化剂的功效具有深远的影响。催化N-芳基无环甲基酮亚胺和非甲基酮亚胺的还原,以高至高收率和对映选择性提供所需的胺。特别是催化剂6e使难于分离的笨重的酮亚胺高效且对映选择性降低,可提供高达99%的收率和97%的ee。事实证明,该催化剂比甲基酮亚胺更优选相对较大的非甲基非环酮亚胺作为底物,这在亚胺的催化不对称还原方面是前所未有的。