Electro-oxidative C(sp)-H/O-H cross-dehydrogenative coupling of phenols and tertiary anilines for diaryl ether formation

The formation of diaryl ethers is generally achieved via transition metal catalyzed etherification reactions (Ullmann, Chan-Lam, Buchwald-Hartwig) with prefunctionalized aryl halide substrates at elevated temperatures. Herein, we report a protocol for electrochemical C(sp 2 )-H/O-H cross-dehydrogenative coupling of phenols and tertiary anilines to synthesize diaryl ethers. The C(sp 2 ) H/O-H coupling product can be obtained under metal- and oxidant-free conditions at room temperature in moderate to excellent yield (up to 83% yield) with high regioselectivity (>99% for para -substitution) and with a broad substrate scope (22 examples). The selective electrochemical oxidation of tertiary anilines in the presence of phenolic reactants leads to diaryl ether products.