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

Dithioesters, which are crucial sulfur derivatives of carboxylic esters, demonstrate broad potential in organic synthesis and biomedicine. However, traditional synthesis methods remain inefficient and pose safety concerns due to the use of toxic sulfur sources, cumbersome procedures, and/or the need for high-temperature conditions. Herein, we successfully synthesize dithioesters in a direct and green manner using elemental sulfur, alkyl bromides, and aromatic aldehydes as raw materials, with catalysis driven by single electron transfer (SET) of metal chalcogenide clusters and hydrogen atom transfer (HAT) from bromide radicals produced in the reaction. In this scheme, dispersant formamide acts both as a dispersant for metal chalcogenide clusters and as a promoter for acylthio radical formation. Significantly, the system shows great substrate compatibility with linear alkyl bromides and aromatic aldehydes, along with benefits from economically accessible raw materials, simple operations, and mild reaction conditions. This study unveils a new approach to thiocarbonyl bond construction, with significant implications for organic and pharmaceutical synthesis.