Revisiting Methyl-Halide Elimination Reactions in Hydrazide Based Hypercoordinate Silicon(IV) Complexes

A group of hypercoordinate silicon(IV) complexes are synthesized by the reactions of O-silylated N,N-dimethylhydrazides with YSiCl3 (Y = cyclohexyl and i-Bu). All the complexes are characterized by H-1, C-13, and Si-29-NMR spectroscopy. The influence of steric and electronic behavior of remote substituents and the groups attached to silicon on the methyl halide elimination reactions of these complexes are discussed. The rate of methyl-halide elimination strongly depends on the nucleophile strength (i.e., I- > Br- > Cl-) and the remote substituent R (R = Me < t-Bu < Ph).