Reactions of group IV organometallic compounds: XVII. Addition reactions of heptamethyldisilazane with benzoyl iso(thio)cyanate and subsequent eliminations

Abstract

Benzoyl isocyanate and isothiocyanate react with heptamethyldisilazane to give 1 1 adducts, which exist as mixtures of the isomers involving 1,3-transfer of trimethylsilyl groups. The adducts from benzoyl isothiocyanate decompose thermally by two βB-elimination processes; one, at temperatures below 100°, givesmethyl isothiocyanate, and the other, at 150°, gives trimethylsilyl isothiocyanate. Migration of trimethylsilyl groups was confirmed by means of NMR measurements at various temperatures. This migration is important in determining the course of subsequent βB-elimination reactions.