Highly Enantioselective Synthesis of Nitrocyclopropanes via Organocatalytic Conjugate Addition of Bromomalonate to α,β-Unsaturated Nitroalkenes
作者:Yi-ning Xuan、Shao-zhen Nie、Li-ting Dong、Jun-min Zhang、Ming Yan
DOI:10.1021/ol900227j
日期:2009.4.2
Highly enantioselective synthesis of nitrocyclopropanes was achieved via the organocatalytic conjugate addition of dimethyl bromomalonate to nitroalkenes and the consequent intramolecular cyclopropanation. 6′-Demethyl quinine was found to be the efficient catalyst. Excellent enantioselectivities, diastereoselectivities, and good yields were obtained for a variety of aryl or heteroaryl nitroethylenes
硝基环丙烷的高度对映选择性合成是通过将溴代丙二酸二甲酯向硝基烯烃的有机催化共轭加成反应以及随后的分子内环丙烷化而实现的。发现6'-脱甲基奎宁是有效的催化剂。对于各种芳基或杂芳基硝基乙烯,获得了优异的对映选择性,非对映选择性和良好的收率。