Cascade C-H Activation/Annulation of Sulfoxonium Ylides with Vinyl Cyclopropanes: Access to Cyclopropane-Fused α-Tetralones.

Rh-catalyzed weak and traceless directing-group-assisted cascade C-H activation and annulation of sulfoxonium ylides with vinyl cyclopropanes as a coupling partner have been accomplished to furnish functionalized cyclopropane-fused tetralones at moderate temperature. The C-C bond formation, cyclopropanation, functional group tolerance, late-stage diversifications of drug molecules, and scale-up are the important practical features.