-Phosphinoamidinato Silylene- and Phosphine-Borylborylene Complexes.

This work describes a straightforward method to synthesize a borylborylene without proceeding via the rearrangement of a diborene. An amidinato amidosilylene [LSiNMe] (L = PhC(NBu)) and PMe were reacted with an -phosphinoamidinato diborane and KC to form a stable silylene-borylborylene and a persistent phosphine-borylborylene , respectively. Compound is stable as the borylene center is well stabilized by the silylene donor and boryl substituent, whereas compound is unstable in solution due to labile PMe. The latter was illustrated by reacting compound with Ar'NC (Ar' = 2,6-MeCH), where Ar'NC displaced PMe and inserted into the -phosphinoamidinate ligand and B-B bond to form compound .