Cu(OTf)2‐Catalyzed Aerobic Cycloisomerization of Alkenyl Sulfones to Furans Using (E)‐β‐Chlorovinyl Ketones and Sodium Sulfinates

Sodium sulfinate addition to (E)‐β‐chlorovinyl ketones followed by the aerobic cycloisomerization of alkenyl sulfone intermediates has been established for the synthesis of 3‐sulfonyl furans. The optimal cycloisomerization catalyst system was identified to be Cu(OTf)2, where molecular oxygen acts as a terminal oxidant. With three points of structural variation in both β‐chlorovinyl ketones and sodium sulfinates, the current aerobic cycloisomerization strategy allows the synthesis of highly functionalized and substituted furan derivatives.