Nucleophilic substitution at silicon: evidence for a parallel with addition reactions to α,β ethylenic ketones

Abstract

The relationship between the stereochemistry of nucleophilic substitution at Si–O and Si–F bonds and the electronic character of the attacking nucleophile (Bu₂ⁱAlH, LiAlH₄, LiAlH₄–4CuI, EtLi, EtMgBr, and Et₂CuMgBr) has been studied; those reagents which favour 1,2-addition to α-enones react with retention of configuration, whereas those which favour 1,4-addition to α-enones react with inversion.