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.