Reactions of ortho-substituted α,α-dibromoacetophenones with nucleophiles: first examples of combined carbophilic and bromophilic attack on C-Br bonds

An efficient method for the formation of alpha-carbonyl-monosubstituted acetophenones from ortho-methoxy-and ortho-hydroxy-alpha,alpha-dibromoacetopheiiones and a range of selected nucleophiles, occurring via a carbophilic substitution/bromophilic substitution/protonation cascade process, is described. In turn, the preparation of alpha,alpha-dibromoacetophenones, isolated in high yields, relies on the neighboring group participation of the ortho-substituents in the starting ortho-substituted acetophenones. (C) 2008 Elsevier Ltd. All rights reserved