Rare Earth Metal Boryl Complexes: Synthesis, Structure, and Insertion of a Carbodiimide and Carbon Monoxide

Among the first of their kind: Scandium boryl complex 1 and its Gd analogue were prepared by reaction of a boryl lithium compound with [Ln(CH2SiMe3)2(THF)x][BPh4] (Ln=Sc, Gd). Reaction of 1 with N,N′-diisopropylcarbodiimide gave bis(amidinate) complex 2, which affords 3 by double CO insertion into the ScB bond, nucleophilic addition of an amidinate, and migration of the SiMe3 to the resulting ketene moiety (see scheme).