Selectfluor‐Mediated Synthesis of Methylene‐Bound Heteroamination and α‐Methylenation of 3‐Acetylindoles Using DMSO as a One‐Carbon Source

ABSTRACT A selectfluor‐mediated metal‐free approach has been developed for the synthesis of methylene‐bound benzotriazolation, triazolation, and pyrazolation of 3‐acetylindoles at 90°C. The reaction is kinetically controlled and uses DMSO as one carbon source. Further, α ‐methylenation of 3‐acetylindoles was observed when benzotriazole, triazole, and pyrazole were absent in the reaction at a higher temperature (120°C). The reaction uses DMSO as one‐carbon synthon and is thermodynamically controlled. The base is needed for α ‐methylenation of 3‐acetylindoles. The current method expands the scope of metal‐free organic reactions and offers new opportunities for developing a library of bioactive indoles for pharmaceutical science.