Chiral Phosphine−Olefin Ligands in the Rhodium-Catalyzed Asymmetric 1,4-Addition Reactions

• Published in: Journal of the American Chemical Society 2007-02, Vol.129 (7), p.2130-2138
• Main Authors: Duan, Wei-Liang, Iwamura, Hiroshi, Shintani, Ryo, Hayashi, Tamio
• Format: Article
• Language: English
• Subjects: Alkenes - chemical synthesis; Alkenes - chemistry; Boronic Acids - chemistry; Bridged Bicyclo Compounds - chemical synthesis; Bridged Bicyclo Compounds - chemistry; Catalysis; Crystallography, X-Ray; Kinetics; Ligands; Molecular Structure; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry; Phosphines - chemical synthesis; Phosphines - chemistry; Rhodium - chemistry
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja0671013

A full overview on the use of chiral phosphine−olefin ligands 1 in the rhodium-catalyzed asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated carbonyl compounds is described. Effective chiral environment of a Rh/1 complex was shown to resemble that of a Rh/(R,R)-Ph-bod* complex by comparing the experimental results as well as the X-ray crystal structures. High catalytic activity of a Rh/1 complex was disclosed and the catalytic cycle involving a trimer−monomer equilibrium was established through mechanistic studies using a reaction calorimeter and 31P NMR spectroscopy. A negative nonlinear effect derived from an inactive trimer−active monomer equilibrium of the catalyst was also successfully observed.