Photochemical Csp2-H bond thiocyanation and selenocyanation of activated arenes, batch and continuous-flow approaches

GABRIELA OKSDATH MANSILLA

Photochemical and Photobiological Sciences

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2022

1474-905X

erein, we report an eco-friendly photochemical oxidative Csp2-H thiocyanation and selenocyanation of activated arenes. The reaction proceeds under Violet LED irradiation in the presence of K2S2O8, which quickly oxidizes KSCN and KSeCN, finally producing arylthio/selenocyanates. Using this benign, atom-economic protocol, the desired chalcogenide products were obtained regioselectively, with isolated yields that range from very good to excellent. Although, mechanistic study indicates that it is difficult to distinguish between a radical to a SEAr reaction mechanism between the photo-induced formed -SCN, for the former, or NCSSCN, for the latter, to the aromatic heterocycles. The inhibition experiment together with the observed reactivity and regioselectivity, would be in agreement with the latter. The synthetic methodology designed could be successfully adapted to continuous-flow systems in a segmented-flow regime, employing the organic phase as the product reservoir. Using this setup,