Weak Base Promoted β-Elimination Reactions in 1-Phenyl-1-propyl Derivatives. Evidence for an Intermediate in the E2C Reaction

Article abstract of DOI:10.1021/jo00217a003

We describe the observation of a nucleophile trigger mechanism in the case of the weak base promoted β-elimination (E2C process) and suggest permutational isomerism of TBP intermediates.Weak bases, namely, bromide and fluoride ions, bring about elimination in a bent transition state to which only a small fraction of a covalent bond to the nucleophile-base and some leaving group departure must be achieved in an orienting intermediate.These studies provide evidence for a TBP structure surrounding C-α in the 1-phenyl-1-propyl system and attribute the equal availability of abstractable H and D of both diastereoisomers to the action of the promoter bases.