Decarboxylative ring-opening of maleic anhydride with a combination of aromatic and aliphatic thiols or an alcohol/thiol mixture for the synthesis of β-thiopropionate thioesters or esters, catalyzed by triphenylphosphine.

In this study, the one-pot reaction of maleic anhydride with a combination of aromatic and aliphatic thiols, or with an alcohol and thiol mixture, in the presence of triphenylphosphine catalyst has been investigated. The reaction with the mixture of thiols occurs in a single step, and despite the presence of two different thiols in the reaction medium, a unique product is formed. The aromatic thiol facilitates the ring-opening of the anhydride, while the aliphatic thiol participates solely in the Michael addition to the intermediate. When a mixture of alcohol and thiol is used in the medium, the reaction proceeds in two steps. In this reaction, the alcohol opens the anhydride ring, and the thiol induces nucleophilic addition to the acrylate intermediate.