Substrate-controlled regioselective dibenzylation of enaminones

Abstract

A substrate-controlled α,α-dibenzylation and O-benzylation-α-benzylation reaction of enaminones with benzyl bromides is described. This divergent strategy provides efficient access to a new class of structurally diverse α,α-dibenzylated products and O-benzylated-α-benzylated products, through adjusting the alkyl or aryl substituent at the β-position of the enaminone. This protocol represents the first example of transition-metal-free-catalyzed and regioselective dibenzylation reactions of alkenes. This approach is notable for its mild and operationally simple conditions, good functional group tolerance, gram-scale reaction and late-stage derivatization.