Synthesis of P-Chiral Phosphine Ligands with Alkynyl Groups

Significance

Many years ago, Imamoto and co-workers discovered stable P-B complexes and used them to synthesize various chiral phosphines. Here he reports the synthesis of P-chiral phosphines containing alkynyl groups. The procedure offers a variety of chiral phosphines, many of which succeeded as ligands in asymmetric reactions such as hydrogenation, conjugate addition and an alkylative ring-opening reaction.