Synthesis of cyclopropanes via palladium-catalyzed [2 + 1] annulations of sulfoxonium ylides and norbornenes

A novel and efficient cyclopropanation reaction of sulfoxonium ylides with norbornene (NBE) derivatives catalyzed by a palladium catalyst has been realized. Such a conversion provides access to a range of cyclopropane-fused norbornene skeletons with exclusive selectivity using sulfoxonium ylides as the carbene precursors.