Dehydrocoupling reactions of amines with silanes catalyzed by [(Et2N)(3)U][BPh4]

Dehydrocoupling reactions of primary amines RNH2 with PhSiH3 were catalyzed by [(Et2N)(3)U][BPh4] to give the corresponding aminosilanes PhSiH3-n(NHR) (n) (n = 1-3), the relative yields of the products were found to be depende nt on the experimental conditions and on the nature of R. For a primary sil ane (PhSiH3), the reactivity of RNH2 follows the order primary > secondary > tertiary. Similar dehydrocoupling reactions using secondary amines with s econdary silanes were found to be less reactive. Homodehydrocoupling of the silane was found not to be a competing reaction at room temperature. The h ydride [(RNH)(2)UH][BPh4] which is plausibly formed in the reaction of [(RN H)(3)U][BPh4] with PhSiH3 is a likely intermediate in the catalytic cycle. (C) 2000 Elsevier Science S.A. All rights reserved.