Palladium-catalyzed regioselective synthesis of mono and bis(arylthiol) alkenes from propargyl carbonate and thiophenol

A palladium catalyzed regioselective reaction of propargylic carbonate with thiophenols and benzene selenol is described. Atom-economic addition of thiols to propargylic carbonates provides an excellent opportunity for effective processes. The reaction proceeds via hydrothiolation to produce mono(arylthiol) alkenes and hydrothiolation followed by Tsuji-Trost type substitution to form bis(arylthiol) alkenes through single and double sequential attack by soft thio nucleophiles by control of the equivalence of thiophenols. This coupling reaction with good tolerance towards functional groups in both propargylic carbonates and thiols furnished a variety of highly functionalized alkenylation products in moderate to excellent yields via the formation of new C-S and C-Se bonds.