Reductive coupling reactions: A new strategy for C(sp³)-P bond formation

The C(sp³)-P bond forming reaction utilizing N-tosylhydrazones as readily available alkylating reagents was developed, which provides a new opportunity for preparing phosphine oxide derivatives with moderate to good yields. This reductive coupling reaction is proposed to proceed through an insertion of copper carbene into P-H bond of H-phosphorus oxides. The salient features of the reaction are operational simplicity and functional-group tolerance.