Enantioselective Synthesis of Alkyne-Substituted Quaternary Carbon Stereogenic Centers through NHC−Cu-Catalyzed Allylic Substitution Reactions with (<i>i</i>-Bu)<sub>2</sub>(Alkynyl)aluminum Reagents
作者:Jennifer A. Dabrowski、Fang Gao、Amir H. Hoveyda
DOI:10.1021/ja2010829
日期:2011.4.6
A catalyticenantioselective method for the formation of alkyne-substituted all-carbon quaternary stereogenic centers is reported. Additions of alkynylaluminums to alkyl-, aryl-, carboxylic ester-, or silyl-substituted allylic phosphates are promoted by 1.0-5.0 mol % loadings of NHC-Cu complexes derived from air-stable and commercially available CuCl(2)·2H(2)O. The requisite Al-based reagents are prepared