Photochemical Ni-Catalyzed Enabled C-O Coupling of Aryl Halides with Phenols

The low nucleophilicity of phenol is a major obstacle in the transition metal-catalyzed synthesis of diaryl ethers. This work presents a mild and efficient strategy for C-O coupling between aryl halides with phenols without the need for an external photosensitizer, catalyzed by the earth-abundant metal nickel under 390-395 nm LED photoexcitation. The method features mild reaction conditions and employs soluble organic amines as bases, significantly enhancing functional group compatibility. Experimental results demonstrate that (hetero)aryl halides bearing diverse electronic effects readily react with phenol to yield the corresponding diaryl ether products in high yields. This broad substrate scope provides a convenient pathway for the efficient synthesis of diaryl ethers, highlighting the catalytic system's potential application in diaryl ether synthesis.