Iodine-Mediated Copper-Catalyzed Efficientα-C(sp2)-Thiomethylation ofα-Oxoketene Dithioacetals with Dimethyl Sulfoxide in One Pot

Abstract

The direct α-Csp2H functionalization and thiomethylation of α-oxoketene dithioacetals (DTAs) has been accomplished with dimethyl sulfoxide (DMSO) in the presence of iodine and a copper(I) salt for the first time. A prerequisite is the in situ iodination of the α-Csp2 atom of dithioacetals that could offer other reaction channels. The operationally simple one-pot protocol includes region-defined consecutive iodination and sulfenylation of the challenging α-Csp2H bond of dithioacetals employing cheap and readily available reagents. DMSO here plays a dual role as thiomethyl source and solvent.