Enantioselective conjugate addition of ketones to nitroalkenes catalyzed by pyrrolidine-sulfamides
作者:Jinjia Wang、Jinhua Lao、Quansheng Du、Shaozhen Nie、Zhipeng Hu、Ming Yan
DOI:10.1002/chir.21987
日期:2012.3
A series of chiral pyrrolidine‐sulfamides were prepared and examined as the catalysts for conjugate addition of ketones to nitroalkenes. Benzoic acid was identified as the most efficient additives for the transformation. Excellent enantioselectivities, diastereoselectivities, and yields were achieved for the reaction of cyclohexanone with β‐aryl nitroethylenes under solvent free conditions. β‐Isopropyl
制备了一系列手性吡咯烷-磺酰胺,并作为催化剂将酮共轭加成到硝基烯烃中。苯甲酸被认为是转化最有效的添加剂。在无溶剂条件下,环己酮与β-芳基硝基乙烯的反应具有出色的对映选择性,非对映选择性和产率。也可以使用β-异丙基硝基乙烯,经过延长的反应时间后,可以得到具有优异对映选择性的产物。比较具有不同侧链的吡咯烷-磺酰胺类有机催化剂的催化行为表明,对映选择性主要受手性吡咯烷单元控制,侧链上的其他手性中心发挥的作用可忽略不计。提出了硫酰胺和硝基之间的氢键相互作用对于硝基链烯的活化和组织良好的过渡态至关重要。手性,2012年。©2012 Wiley Periodicals,Inc.。