Palladium(0)-Catalyzed, Copper(I)-Mediated Coupling of Cyclic Thioamides with Alkenylboronic Acids, Organostannanes, and Siloxanes

The Pd-catalyzed cross-coupling of cyclic thioamides and thioureas with alkenylboronic acids, vinyl- and (het)aryl-stannanes, and arylsiloxanes in the presence of stoichiometric amounts of a Cu(I) cofactor is described. The desulfitative C-C cross-coupling protocol of the Liebeskind-Srogl type is performed under neutral conditions and can be applied to a range of heterocyclic structures with embedded thioamide fragments. Employing controlled microwave irradiation at 100 degrees C utilizing either a single-mode reactor or a multimode parallel reaction platform, cross-couplings can generally be completed within 1-3 h and proceed in good yields.