Insertion Reactions and Catalytic Hydrophosphination of Heterocumulenes using α-Metalated N,N-Dimethylbenzylamine Rare-Earth-Metal Complexes

The reactivity of homoleptic α-metalated dimethylbenzylamine lanthanide complexes (α - Ln(DMBA) 3; Ln = La, Y; DMBA = α-deprotonated dimethylbenzylamine) was probed through a series of stoichiometric insertion and catalytic hydrophosphination reactions. Both rare-earth-metal species inserted 3 equiv of various carbodiimides to form the corresponding homoleptic amidinates. α - La(DMBA) 3 was also found to be a useful precatalyst for the room-temperature hydrophosphination of heterocumulenes to form phosphaguanidines, phosphaureas, and phosphathioureas in moderate to excellent isolated yields. Furthermore, through a series of stepwise stoichiometric protonation and insertion reactions, a plausible mechanism for the hydrophosphination catalysis was investigated.