Palladium-Catalyzed Cyclization: Regioselectivity and Structure of Arene-Fused C₆₀ Derivatives

Abstract

The palladium-catalyzed cyclization on the fullerene C₆₀ cage has been achieved using several aryl halides and C₆₀. This reaction was found to be accelerated by the addition of pivalic acid, which can be rationally explained by the computational study based on the concerted metalation-deprotonation mechanism. We also demonstrated the regioselective π-functionalization using prefunctionalized designed molecules possessing the same substructure on the C₆₀ cage. The single crystal X-ray analysis and electrostatic potential map revealed that the orientation of entrapped H₂O inside the naphthalene-fused open-cage C₆₀ derivative is electrostatically demanded due to the naphthalene-fusion and construction of the opening.