Copper-Catalyzed Enantioselective Conjugate Addition of Grignard Reagents to Acyclic Enones
作者:Fernando López、Syuzanna R. Harutyunyan、Adriaan J. Minnaard、Ben L. Feringa
DOI:10.1021/ja046632t
日期:2004.10.1
A highly enantioselective Cu-catalyzed addition of Grignard reagents to acyclic aliphatic enones is described. In the presence of 5 mol % of CuBr.SMe2 and 6 mol % of JosiPhos diphosphine aliphatic enones react with Grignard reagents to provide beta-substituted linear ketones with high yields, regio-, and enantioselectivities.
Highly Enantioselective Conjugate Addition of AlMe3 to Linear Aliphatic Enones by a Designed Catalyst
作者:Paul K. Fraser、Simon Woodward
DOI:10.1002/chem.200390087
日期:2003.2.3
of AlMe(3) to linear aliphatic enones in THF at -40 to -48 degrees C in the presence of [Cu(MeCN)(4)]BF(4). At ligand loadings of 5-20 mol %, enantioselectivities of 80-93 % are realised for most substrates. To attain these values, the use of highly pure AlMe(3) is mandatory. The presence of methylalumoxane (MAO), derived by hydrolysis, leads to reduced enantioselectivity and a conjugate addition product