Remarkable Effect of Silyl Groups on Asymmetric Induction in a Conjugate Addition Reaction with <i>O</i>-Methylnorephedrine-Based<i> N</i>-Silylamidocuprates
作者:Steven H. Bertz、Craig A. Ogle、Abhinav Rastogi
DOI:10.1021/ja0455805
日期:2005.2.1
with chalcone, a classic substrate for studies of organocuprate conjugate addition. For example, the butyl N-diphenylmethylsilylamidocuprate (T = Bu) affords a 99.2% ee (99% yield) of (S)-3-butyl-1,3-diphenyl-1-propanone. The remarkably high yields with this and other silyl ligands are attributed to the extraordinary activating effect of a beta-silicon atom on organocuprate reactions. The high ee is
Scalemic N-甲硅烷基氨基铜酸盐,由 O-甲基去甲麻黄碱在两瓶程序中制备,具有极强的反应性,并与查耳酮(一种用于研究有机铜酸盐缀合物加成的经典底物)产生极好的对映体过量。例如,丁基 N-二苯基甲基甲硅烷基氨基铜酸盐 (T = Bu) 提供 99.2% ee(99% 产率)的 (S)-3-丁基-1,3-二苯基-1-丙酮。这种和其他甲硅烷基配体的显着高产率归因于β-硅原子对有机铜酸盐反应的非凡活化作用。与未取代或甲基取代的类似物相比,高 ee 是甲硅烷基配体尺寸较大的结果。