Visible Light-Induced Deoxygenation and Allylation/Vinylation of Pyridyl Ethers.

The generation of alkyl radicals by deoxygenation of unactivated ethers under visible light catalysis is a hitherto unmet challenge. Herein, we report a visible light-induced deoxygenation of pyridyl ethers via formation of their pyridinium salts. The generated benzylic radicals further react with allyl/alkenyl sulfones to provide a series of coupling products in good to moderate yields. This process is proposed to undergo a reductive quenching cycle, which was elucidated by chemical, optical, and electrical experiments.