Staudinger Reaction as a Way Out To Avoid Cyclization in the Reaction of Silylated Dichloro(hydrazino)phosphane with Trimethylsilyl Azide

Reaction of dichloro-N,N',N'-[tris(trimethylsilyl)]hydrazinophosphane (1) with Me3SiN3 leads after an initial chlorine/ azide exchange in a Staudinger reaction to a new phosphorus azide. The in situ formed phosphoranimine reacts with GaCl3 by Me3SiCl elimination, resulting in a phosphoranimino-dichlorogallane, which dimerizes to a Ga2N2-four-membered ring. The overall reaction at ambient temperature represents a fast and clean high-yielding reaction (reaction tine 2 h). The dimer of the formed azido-phosphoranimino-dichlorogallane was fully characterized and shown to be stable to temperatures above 103 C. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)