Oxidative C(sp(2))-H Phosphonation of Aldehyde Hydrazones.

A K2S2O8/Cu(OAc)2-mediated oxidative C-H/P-H cross-coupling of aldehyde hydrazones with diphenylphosphine oxide for the direct preparation of functionalized α-iminophosphine oxides is reported. The reaction shows good functional group tolerance and proceeds smoothly under mild conditions. This strategic protocol for C-P bond formation is facilitated by a net oxidative aminyl radical-polar crossover process.