Copper-Catalyzed Oxidative Decarboxylative Arylation of Benzothiazoles with Phenylacetic Acids and α-Hydroxyphenylacetic Acids with O2 as the Sole Oxidant

A Cu(II)-catalyzed oxidative decarboxylative synthesis of 2-aryl benzothiazole from phenylacetic acids and alpha-hydroxyphenylacetic acids has been developed. This reaction proceeds via Cu(II)-catalyzed decarboxylation, C-H bond oxidation, ring-opening, and condensation steps in a one-pot protocol with dioxygen as the sole terminal oxidant. Various functional groups were tolerated under standard conditions, and isolated yields were as high as 95%.