A Tin-Free, Radical Photocatalyzed Addition to Vinyl Sulfones

Radical conjugate addition onto vinyl sulfones was achieved by means of a convenient, tin-free procedure. This was based on the photocatalyzed C?H bond activation in aldehydes, amides, ethers and even cycloalkanes by using tetrabutylammonium decatungstate (TBADT). The reaction was likewise effective for the functionalization of beta-substituted vinyl sulfones. The products are useful building blocks and were obtained in satisfactory yields both under artificial UV light and under sunlight, so demonstrating the green potential of the process.