Direct and green synthesis of dithioesters enabled by dispersant-collaborative semiconductor cluster photocatalysis

Dithioesters, which are crucial sulfur-containing derivatives of carboxylic esters, demonstrate broad potential in organic synthesis and biomedicine. However, traditional synthetic methods remain inefficient and pose safety concerns owing to the use of toxic sulfur sources, cumbersome procedures, and/or harsh high-temperature conditions. Herein, we report a direct and green strategy for the synthesis of dithioesters using elemental sulfur, alkyl bromides, and aromatic aldehydes as raw materials. The reaction is catalyzed by metal chalcogenide clusters through single-electron transfer, in combination of hydrogen atom transfer from bromide radicals produced in situ. In this system, formamide acts as both a dispersant for the metal chalcogenide clusters and a promoter for acylthio radical formation. Notably, the method shows great substrate compatibility with linear alkyl bromides and aromatic aldehydes while offering advantages such as low-cost feedstocks, simple operational procedures, and mild reaction conditions. This study unveils a new approach to thiocarbonyl bond construction and holds significant promise for applications in organic and pharmaceutical synthesis.