Visible Light Photoredox-Catalyzed Aerobic Oxidative Sulfonylation of Alkynes with Sodium Sulfinates: An Easy Access to β-Keto Sulfones

An efficient and green synthesis of β-keto sulfones by the reaction of alkynes and sodium sulfinates through a radical pathway using an organophotocatalyst is reported. The reaction was catalyzed by Eosin Y at room temperature involving air oxygen as clean and cheapest oxidant. The proposed protocol utilizes readily available sodium sulfinates as sulfonylating reagents and light as a cost-effective and environmentally benign energy source to offer a general approach for the synthesis of β-keto sulfones.