Highly Enantioselective Conjugate Addition of AlMe3 to Linear Aliphatic Enones by a Designed Catalyst

✍ Scribed by Paul K. Fraser; Simon Woodward

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 162 KB
• Volume: 9
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.200390087

✦ Synopsis

Abstract

2‐Hydroxy‐2′‐alkylthio‐1,1′‐binaphthyl compounds are catalytic promoters of the 1,4‐addition of AlMe~3~ to linear aliphatic enones in THF at −40 to −48 °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.