Iron(III) Chloride Catalyzed Oxidative Coupling of Aromatic Nuclei

Easily available and nontoxic FeCl3 catalyzes intramolecular oxidative Coupling for the direct construction of the phenanthrene ring using meta-chloroperbenzoic acid as sole oxidant at room temperature in excellent yields. The mechanistic investigations show that FeCl3-catalyzed coupling proceeds through the heterolytic coupling (A(+) + B). The catalytic approach has been applied to intermolecular biaryl coupling of 2-naphthols and phenol ether.