Access to α-Furyl Sulfones via Three-Component Reactions Involving Ketene Dithioacetals, Acetylenes, and TosMIC

A practical protocol for the direct assembly of sulfonylated furans has been developed through a Pd/Cu-cocatalyzed three-component reaction of α-acyl ketene dithioacetals with terminal alkynes and tosylmethyl isocyanide (TosMIC), wherein TosMIC functions as a sulfonyl source. This tandem reaction simultaneously constructs a furan scaffold and a sulfone section within a single procedure via a sequential desulfurative Sonogashira coupling/1,6-addition/5-<i>exo</i>-<i>dig</i> cyclization/protonation cascade. The operational simplicity, broad substrate scope, good functional group tolerance, and late-stage derivatizations make this methodology attractive to both synthetic and medicinal chemistry.