One-ligand Catalytic Asymmetric Deprotonation of a Phosphine Borane: Synthesis of <i>P</i>-Stereogenic Bisphosphine Ligands
作者:Johan Granander、Francesco Secci、Steven J. Canipa、Peter O’Brien、Brian Kelly
DOI:10.1021/jo200708e
日期:2011.6.3
A new protocol for the catalytic asymmetric deprotonation of a phosphine borane using s-BuLi and sub-stoichiometric quantities of chiral diamines is reported. The method involves three sequential additions of s-BuLi, and use of (-)-sparteine or the (+)-sparteine surrogate facilitates access to P-stereogenic phosphines with opposite configuration. The method is exemplified by the catalytic asymmetric synthesis of each enantiomer of precursors to QuinoxP*, trichickenfootphos, and Mini-PHOS.
C1-symmetric bisphosphine ligands and their use in the asymmetric synthesis of pregabalin
申请人:Bao Jian
公开号:US20050228190A1
公开(公告)日:2005-10-13
Materials and methods for preparing (S)-(+)-3-(aminomethyl)-5-methyl-hexanoic acid and structurally related compounds via enantioselective hydrogenation of prochiral olefins are disclosed. The methods employ novel chiral catalysts, which include C
1
-symmetric bisphosphine ligands bound to transition metals.
Highly Selective Asymmetric Hydrogenation Using a Three Hindered Quadrant Bisphosphine Rhodium Catalyst
作者:Garrett Hoge、He-Ping Wu、William S. Kissel、Derek A. Pflum、Derek J. Greene、Jian Bao
DOI:10.1021/ja048496y
日期:2004.5.1
synthesis of both enantiomers of ligand2 and rhodium complex 5 is presented. The crux of the synthesis is a chiral HPLC separation of the enantiomers of 4. Rhodium complex 5 possesses three hindered quadrants in the steric environment within which a substrate binds. Evidence is presented that this configuration leads to high enantioselectivity (>99% ee) for rhodium-catalyzed asymmetric hydrogenation of