Key Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University, Shenzhen Graduate School, Shenzhen, 518055 (China) http://web.pkusz.edu.cn/huang.
Angew Chem Int Ed Engl. 2015 Dec 14;54(51):15414-8. doi: 10.1002/anie.201508371. Epub 2015 Oct 30.
The aza-Michael addition reaction is a vital transformation for the synthesis of functionalized chiral amines. Despite intensive research, enantioselective aza-Michael reactions with alkyl amines as the nitrogen donor have not been successful. We report the use of chiral N-heterocyclic carbenes (NHCs) as noncovalent organocatalysts to promote a highly selective aza-Michael reaction between primary alkyl amines and β-trifluoromethyl β-aryl nitroolefins. In contrast to classical conjugate-addition reactions, a strategy of HOMO-raising activation was used. Chiral trifluoromethylated amines were synthesized in high yield (up to 99 %) with excellent enantioselectivity (up to 98 % ee).
氮杂迈克尔加成反应是合成功能化手性胺的重要转化。尽管研究已经很深入，但作为氮供体的烷基胺的对映选择性氮杂迈克尔加成反应还没有成功。我们报告了使用手性 N-杂环卡宾（NHCs）作为非共价有机催化剂，促进伯烷基胺和β-三氟甲基β-芳基硝基烯烃之间的高选择性氮杂迈克尔加成反应。与经典的共轭加成反应不同，采用了 HOMO-raising 活化策略。手性三氟甲基化胺以高收率（高达 99%）和优异的对映选择性（高达 98%ee）合成。
