Cinchona-Derived Picolinamides: Effective Organocatalysts for Stereoselective Imine Hydrosilylation
作者:Pedro C. Barrulas、Andrea Genoni、Maurizio Benaglia、Anthony J. Burke
DOI:10.1002/ejoc.201403180
日期:2014.11
Picolinamide–cinchona organocatalysts for the successful enantioselective reduction of ketomines were developed. For the first time, a new type of chiral Lewis base, a cationic species, is reported to efficiently organocatalyze the addition of trichlorosilane to imines. Excellent yields with good to high enantioselectivities (up to 91 %) were obtained in the reduction of differently substituted substrates
开发了用于成功对映选择性还原酮胺的吡啶甲酰胺-金鸡纳有机催化剂。据报道,一种新型手性路易斯碱(一种阳离子物质)可有效地有机催化三氯硅烷与亚胺的加成。在不同取代的底物的还原中获得了具有良好到高对映选择性(高达 91%)的优异产率。值得注意的是,观察到亚胺氢化硅烷化的转换频率非常高;事实证明,所选催化剂即使在仅 1 mol% 的负载量下也具有活性。负载量进一步降低到 0.5 mol%,并且在非常短的反应时间(15 分钟)内达到了非常令人印象深刻的不对称催化剂效率速度值。