Homoleptic Lanthanide Alkyl and Amide Precatalysts Efficiently Mediate Intramolecular Hydrophosphination/Cyclization. Observations on Scope and Mechanism

Homoleptic lanthanide alkyls of the form Ln[CH(SiMe 3 ) 2 ] 3 (Ln = La, Nd, Sm, Y, Lu) and amides of the form Ln[N(SiMe 3 ) 2 ] 3 (Ln = La, Nd, Sm, Y) serve as efficient precatalysts for intramolecular homogeneous hydrophosphination. Both phosphinoalkynes and phosphinoalkenes undergo cyclization to the corresponding heterocyclic structures.