Contributions to the chemistry of silicon-sulphur compounds LVI. The imidazole catalyzed alcoholysis of the isosteric isobutyl(isopropoxy)silanethiols i-Bun(i-PrO)3-nSiSH (n = 0-3)

Article abstract of DOI:10.1016/0022-328X(90)80003-I

The kinetics of the imidazole-catalyzed alcoholysis of the isosteric silanethiols i-Bu_n(i-PrO)_3-nSiSH (I) with n = 0-3 in benzene and acetonitrile have been investigated.The alcoholysis of Si-S bond in I is generally first order with respect to both the silanethiol and the catalyst.At low alcohol concentrations the order with respect to alcohol tends to be zero.A mechanism involving an attack of a nucleophilic catalyst on silicon in I in the rate-determining step is proposed.In MeCN solution the reactivities of silanethiols decrease in the sequence i-Bu(i-PrO)2SiSH > i-Bu2(i-PrO)SiSH > (i-PrO)3SiSH > i-Bu3SiSH.The anomeric effect seems to determine the conformations and the reactivities of these silanethiols.