Photochemical Halogen-Bonding Promoted Synthesis of Vinyl Sulfones via Vinyl and Sulfonyl Radicals.

A photochemical halogen-bonding-assisted synthesis of vinyl sulfones via radical-radical cross-coupling of vinyl bromines and sodium sulfinates is developed. This methodology offers a facile and efficient approach to various vinyl sulfones with excellent functional group tolerance under metal-, photocatalyst-, base-, and oxidant-free conditions. The reaction is also applicable for the late-stage functionalization of drug molecules and the hectogram scale. Moreover, instead of sodium sulfites being prepared, these reactions could also be conducted using sulfonyl chlorides in a one-pot method.