Diethylzinc‐Mediated Cross‐Coupling Reactions between Dibromoketones and Monobromo Carbonyl Compounds

Abstract

AbstractA novel route to synthesize 1,4‐dicarbonyl compounds is described. α,α‐Dibromoketones generate zinc enolates through a diethylzinc‐mediated halogen‐metal exchange and react with α‐bromocarbonyl compounds to furnish 1,4‐dicarbonyl compounds via a second generation of zinc enolates. This cross‐coupling reaction is enabled by the chemoselective formation of zinc enolates from α,α‐dibromoketones in the presence of α‐bromocarbonyl compounds. Chiral 1,4‐dicarbonyl compounds can be obtained via the enantioselective bromination of aldehydes using a chiral secondary amine catalyst and a subsequent cross‐coupling reaction between the resulting chiral α‐bromoaldehydes and α,α‐dibromoacetophenones.