Visible-Light-Induced Reductive Coupling of Arylacetylenes with Benzothiazole Sulfones

In this study, we propose heavy-metal-free reductive coupling of arylacetylenes with benzothiazole sulfones. The reactions of alkyl or benzylic benzothiazole sulfones with arylacetylenes are successfully performed in the presence of Hantzsch esters and K2CO3 under visible-light irradiation to afford 1,2-disubstituted alkenes in moderate to good yields, with Z-isomer as the major product. The utility of this protocol is expanded to a-deuterative coupling using a deuterated Hantzsch ester, furnishing the corresponding alkenes with high deuterium incorporation.

Automated summary

In this study, a heavy-metal-free reductive coupling of arylacetylenes with benzothiazole sulfones is proposed. The reactions of alkyl or benzylic benzothiazole sulfones with arylacetylenes are successfully carried out in the presence of Hantzsch esters and K2CO3 under visible-light irradiation, resulting in moderate to good yields of 1,2-disubstituted alkenes, with the Z-isomer as the major product. The utility of this protocol is expanded to a-deuterative coupling, providing the corresponding alkenes with high deuterium incorporation.