Highly Enantioselective 1,4-Michael Additions of Nucleophiles to Unsaturated Aryl Ketones with Organocatalysis by Bifunctional Cinchona Alkaloids
作者:Cristina G. Oliva、Artur M. S. Silva、Diana I. S. P. Resende、Filipe A. A. Paz、José A. S. Cavaleiro
DOI:10.1002/ejoc.201000273
日期:——
The development of general and efficient asymmetric organocatalytic additions of malononitrile and nitromethane to 1,5-diarylpenta-2,4-dien-1-ones (cinnamylideneacetophenones) catalyzed by cinchona organocatalysts is reported. The reactions afforded excellent enantioselectivities (up to 99 %), high yields (up to 97 %), and exclusive 1,4-addition regioselectivities. The potential of these new enantioselective