Reaction of benzyl phenyl ketazine with PCl3: synthesis of substituted 1,2,3-diazaphosphole and its reactions with strong nucleophiles and bases

The reaction of benzyl phenyl ketazine with PCl 3 in tetrahydrofuran affords 2-(1,2-diphenylvinyl)-4,5-diphenyl-2 H -[1,2,3]diazaphosphole ( 1 ). An unusual 1,3-addition of methyllithium at the nitrogen (N-Li) and phosphorus (P-Me) atoms of diazaphosphole was discovered. The reduction peak potentials of diazaphosphole ( 1 ) and the starting ketazine were measured by cyclic voltammetry.