Synthesis of Fused Dihydroazepine Derivatives of Fullerenes by a Rh?Catalyzed Cascade Process

A synthetic methodology is reported that functionalizes C60 and C70 fullerenes with dihydroazepine rings by a cascade reaction encompassing rhodium-catalyzed cycloisomerization of 1,5-bisallenes [4+2] cycloaddition. This transition metal-catalyzed provides versatile step-economical approach to the synthesis 6,7-membered polyheterocyclic fullerene adducts. Electrochemical characterization products obtained ventures their application in organic perovskite photovoltaic devices.