Dual Inert C–H\nBond Site-Selective Activations\nEnabled by Pd/Norbornene-Mediated Cascade Cyclization toward Medium-Sized\nPolyheterocyclic Methylene Sulfoximines

A Pd/norbornene-mediated three-component\nmodular one-step reaction\nfacilitated by dual C–H bond activation and cascade cyclization\nis reported. This procedure uses norbornene as a catalyst in the Catellani-type\nreaction and as an alkylating building block to accomplish the dual\nunactivated C–H bond functionalization protocol, which results\nin the production of polyheterocyclic eight-membered sulfoximines\nwith an indene-fused moiety. This mild, scalable protocol’s\nwide substrate range makes it ideal for site-selective dual C–H\nfunctionalization at the highly chemoselective aryl sites.