Synthesis of Benzothiazoles via Photooxidative Decarboxylation of α-Keto Acids

Herein, synthesis of benzothiazoles via decarboxylative cross-coupling between alpha-keto acids and 2-aminothiophenols under blue LED irradiation without using any photocatalyst or metal at room temperature is described. The formation of benzothiazole is driven by the EDA (electron donor-acceptor) complex formed between alpha-keto acid and 2-aminothiophenol. This methodology gives easy access to 2-substituted and -unsubstituted benzothiazoles in moderate to good yields. alpha-Keto acids and 2-aminothiophenols bearing different functional groups were easily transformed under the given conditions.