4-Trifluoromethanesulfonamidyl prolinol tert-butyldiphenylsilyl ether as a highly efficient bifunctional organocatalyst for Michael addition of ketones and aldehydes to nitroolefins
作者:Chao Wang、Chun Yu、Changlu Liu、Yungui Peng
DOI:10.1016/j.tetlet.2009.02.211
日期:2009.5
4-Trifluoromethanesulfonamidyl prolinol tert-butyldiphenylsilyl ether bifunctional organocatalyst 3a is a highly efficient catalyst for the asymmetric Michael addition reactions of ketones and aldehydes to nitrostyrenes, leading to syn-selective adducts with excellent yields (>99%), high diastereoselectivities (up to 99:1 dr) and excellent enantioselectivities (up to 99% ee). Control experiments suggested that the
4-三氟甲烷磺酰胺基脯氨醇叔丁基二苯基甲硅烷基醚双官能团有机催化剂3a是酮和醛不对称迈克尔加成反应成硝基苯乙烯的高效催化剂,可生成具有良好收率(> 99%),高非对映选择性(高达99%)的顺式选择性加合物:1 dr)和出色的对映选择性(高达99%ee)。对照实验表明,在吡咯烷环的4位大基团(–CH 2 OTBDPS)与磺酰胺基之间的反式关系对于实现高收率和立体选择性很重要。