Hydrophosphination of Propargylic Alcohols and Amines with Phosphine Boranes

Abstract

The first uncatalyzed hydrophosphinations of propargylic amines and alcohols with phosphine– borane complexes are described. The reactions proceed at ambient temperature or below without the use of protecting groups or the need to handle pyrophoric secondary phosphines, furnishing air-stable phosphineborane–amines and alcohols in good yields. Utilization of chiral propargylic substrates and unsymmetrical secondary phosphineboranes leads to diastereomeric <i>P</i>-chiral products that can be separated by fractional crystallization or chromatography. Initial applications of these new P–X species to asymmetric catalysis are detailed