The direct thioesterification of aldehydes with disulfides via NHC-catalyzed carbonyl umpolung strategy

An efficient N-heterocyclic carbene (NHC)-catalyzed direct thioesterification of aldehydes and α,β-unsaturated aldehydes (enals) with diaryl disulfides is reported. The protocol involves carbonyl umpolung reactivity of aldehydes and enals in which the carbonyl carbon attacks nucleophilically on diaryl disulfides to afford thioesters and α,β-unsaturated thioesters, respectively. However, aliphatic aldehydes are not suitable substrates for this reaction. No by-product formation, complete atom-economy, shorter reaction time, ambient temperature, operational simplicity, and high yields are the salient features of the present procedure.