A New Class of Urea-Substituted Cinchona Alkaloids Promote Highly Enantioselective Nitroaldol reactions of Trifluoromethylketones
作者:Carole Palacio、Stephen J. Connon
DOI:10.1021/ol103089j
日期:2011.3.18
The first class of bifunctional cinchona-alkaloid catalysts incorporating a urea moiety at C-5′ has been developed. These materials catalyze the efficient and highly enantioselective 1,2-addition of nitromethane to trifluoromethylketones to form synthetically pliable products incorporating a quaternary stereocenter. Excellent product yields and levels of enantiomeric excess are possible, and the optimum
已经开发出在C-5'处结合有脲部分的第一类双功能金鸡纳生物碱催化剂。这些材料催化硝基甲烷向三氟甲基酮的高效且高对映选择性的1,2-加成反应,从而形成具有四级立体中心的可合成柔韧性的产品。极好的产物收率和对映体过量水平是可能的,并且最佳的催化剂结构能够以前所未有的对映选择性促进涉及烷基三氟甲基酮的亨利反应。