Method for enantioselective synthesis of phosphorus-stereogenic phosphines
The present invention relates to a process for preparing an enantioenriched phosphorus-stereogenic, tertiary phosphine. Secondary phosphines are contacted with an alkyl halide and base in the presence of a chiral metal catalyst thereby producing the enantioenriched phosphorus-stereogenic, tertiary phosphine for subsequent use in homogeneous catalysis reactions.
1. A method for preparing an enantioenriched phosphorus-stereogenic, tertiary phosphine comprising contacting, at a temperature of from −50° C. to 25° C., a secondary phosphine with an alkyl halide and base in the presence of a chiral metal catalyst thereby preparing an enantioenriched phosphorus-stereogenic, tertiary phosphine, wherein the alkyl halide comprises benzyl halide and the chiral metal catalyst comprises Pt(chiral ligand)(Y)(Z), wherein
Y and Z are independently linear, branched, or cyclic alkyl; aryl; or halide groups, or combinations thereof.
2. The method of claim 1 wherein said secondary phosphine and alkyl halide are present at a ratio of from 1:0.5 to 1:2 and said secondary phosphine and chiral metal catalyst are present at a ratio of from 40:1 to 10:1.