Direct Allylic C(sp3)-H Alkylation with 2-Naphthols via Cooperative Palladium and Copper Catalysis: Construction of Cyclohexadienones with Quaternary Carbon Centers

Oxidative allylic C-H alkylation with 2-naphthols was accomplished with excellent chemoselectivities and broad substrate scope through Pd(PPh₃)₄/Cu(MeCN)₄PF₆ cooperative catalysis under mild base-free conditions. Special tolerance was observed with peptides, allowing late-stage modifications of peptides. The transformation provides a general protocol to obtain functionalized cyclohexadienones with quaternary carbon centers under two alternative sets of conditions and serves as a complementary catalysis system for the dearomatization of 2-naphthols.