Sulfoxonium ylides are highly stable carbene precursors, serving as a safer alternative to diazo compounds as they that do not generate gases as byproducts. Sulfoxonium ylides have been shown to be effective in a wide array of transition metal catalyzed C-H functionalization and coupling reactions.

For additional technical information see Ketosulfoxonium Ylides: Safe, Versatile Carbene Equivalents

Rhodium(III)-catalyzed C−H functionalization of C-alkenyl azoles with sulfoxonium ylides for the synthesis of bridgehead N-fused[5,6]-bicyclic heterocycles