Reactivity of N-phenyl silylated ketenimines with electrophilic reagents

We report the reactivity of new Cp silylated ketenimines (4, 5, 6) and lithiated-silylated ketenimine 3 [easily generated from lithiated S-methyl-N-phenyl-trimethylsilylethanimidothioate 2] toward electrophilic reagents. Reactions of these ketenimines with strong electrophilic reagents such as sulfanyl chloride (PhSCl) gave access to new sulfanylated ketenimines. With less reactive species [benzenesulfinyl chloride (PhS(O)Cl), p-toluenesulfonyl chloride, trimethylhalosilanes, diisopropyl chlorophosphate, acetyl chloride and propylene oxide] and 3, the addition took place either on CP or on the nitrogen atom leading to relatively unstable functionalised ketenimines or new silylated ynamines respectively. (C) 1999 Elsevier Science Ltd. All rights reserved.