Desulfitative Pd-catalysed coupling reaction using benzenesulfonyl chlorides and enones as the coupling partners.

International audienceThe reaction of benzenesulfonyl chlorides with enones was investigated. β-Ionone and benzalacetone in the presence of a palladium catalyst were found to afford the conjugate addn. products instead of the expected Heck type products. The reaction tolerates a wide variety of substituents on the benzenesulfonyl chloride. It should be noted that no cleavage of the C-Br and C-I bonds was obsd. in the course of the reactions with 4-bromo- or 4-iodobenzenesulfonyl chlorides, allowing further transformations. For example, using 4-bromobenzenesulfonyl chloride as the central unit, consecutive conjugate addn. and subsequent arylation allowed access to substituted bi(hetero)aryls