Metal-free amino-controlled electrochemical intramolecular C–O and C–N couplings by site-selective activation of aryl C–N and C–O bonds

An unprecedented metal-free electrochemical method for the divergent synthesis of complex dibenzo[b,d]furans and 9H-carbazoles via amino-assisted selective intramolecular C–O or C–N couplings of amino-2-(2-aminoaryl)phenols is described, which features low cost, controllable chemoselectivity, broad substrate scope and excellent functional group tolerance. Experimental and cyclic voltammetry analysis show that amino activating groups located at 4 or 5 position of the phenol ring can reduce the oxidation potential to selectively activate aryl C–N and C–O bonds, thus achieving intramolecular C–O and C–N couplings, respectively.