Aerobic oxidative synthesis of benzimidazoles by flavin photocatalysis.

Flavin photocatalysis were utilised for an aerobic oxidative reaction between arylamines and o-phenylenediamine. This metal-free reaction proceeded in methanol under visible light irradiation and consumed only atmospheric molecular oxygen, providing a novel eco-friendly method for the synthesis of benzimidazoles.

Aerobic cross-dehydrogenative coupling of toluenes and o-phenylenediamines by flavin photocatalysis for the facile synthesis of benzimidazoles.

Herein, we demonstrate a green atom-economical synthesis of benzimidazoles via the flavin-photocatalysed aerobic oxidative cross-dehydrogenative coupling of toluenes and o-phenylenediamines. The proposed metal-free reaction proceeds in methanol/H2O under visible light irradiation by consuming only molecular oxygen from atmospheric air and produces only water as waste.