The Reactions of Substituted Germyl- and Silylhydrazines with BX₃ and CY₂ Acceptor Species

Abstract

Boron trimethyl reacts with each of the organometalloid-hydrazine derivatives Me 2 NN(R)GeMe 3 (R = H, Me, SiMe 3 ) except Me 2 NN(SiMe 3 )GeMe 3 , and with Me 2 NNHSiMe 3 , forming 1:1 adducts. With Me 2 NN(SiMe 3 )GeMe 3 and BMe 3 , no adduct was formed even at low temperatures. On the basis of p.m.r. spectra, the metalloid-substituted nitrogen atom rather than the terminal nitrogen, is indicated as the basic center at which adduct formation occurs. With BF 3 , the Si—N and Ge—N bonds of the hydrazine derivatives were cleaved, again indicating attack at the central nitrogen atom. In a series of experiments involving CY 2 (Y = O, S) and Me 2 NN(R)MMe 3 (R = H, Me, SiMe 3 ; M = Si, Ge), reaction occurred readily for R = H, but less readily for R = Me and for the compound Me 2 NN(GeMe 3 ) 2 , while no reaction was observed for the compounds Me 2 NN(SiMe 3 ) 2 and Me 2 NN(SiMe 3 )GeMe 3 , even when heat or basic catalysts were employed. Reaction products, carbamate and thiocarbamate derivatives, Me 2 NN(R)C(Y)YMMe 3 , were characterized on the basis molecular weight, i.r., p.m.r., and mass spectroscopy, and m.p. data. Ease of formation is discussed in terms of electronic and steric effects.