TWOFOLD INSERTION OF ISOCYANIDES INTO THE GA-GA BOND OF TETRAKIS[BIS(TRIMETHYLSILYL)METHYL]DIGALLANE(4)

Tetrakis[bis(trimethylsilyl)methyl]digallane (4) (1) reacts with tert- butyl or aryl isocyanides (aryl = phenyl, o-methylphenyl, o-methoxyphe nyl, p-methoxyphenyl) by a twofold insertion of the central carbon ato ms into the Ga-Ga bond and formation of C-C single bonds. 1,4-Diazabut adiene derivatives bound to two R(2)Ga groups are formed (2-6), which in contrast to an aluminium analog exhibit only weak interactions betw een the imine nitrogen atoms and the coordinatively unsaturated galliu m atoms as indicated by NMR spectroscopy and the long Ga-N distances i n the molecular structures of three products: 2 (R = C6H5), 4 (R = o-M eOC(6)H(4)), and 6 (R = CMe(3)).