9-BBN and chloride catalyzed reduction of chlorophosphines to phosphines and diphosphines.

The commercially available Lewis acid, 9-BBN and Lewis basic [Et 4 N]Cl are used as catalysts for the reduction of chlorophosphines R 2 PCl in the presence of phenylsilane. Aryl-chlorophosphines afford primarily diphosphines (P 2 R 4 ) while secondary phosphines predominate for alkyl-substituted precursors. Use of the combined catalysts leads to reduced reaction time and temperature, providing a rapid, scalable, and facile protocol for the preparation of diphosphines or secondary phosphines.