Synthesis of 1-naphthols via Cp*Co(iii)-catalyzed C-H activation and cyclization of sulfoxonium ylides with alkynes

A highly practical and efficient synthesis of 1-naphthols was developed via Cp*Co(iii)-catalyzed C-H activation and cascade [4 + 2] cyclization between sulfoxonium ylides and alkynes, during which the sulfoxonium ylide functioned as a traceless directing group. This method features operational simplicity, redox-neutral reaction conditions, excellent regioselectivity and good substrate compatibility, and various 1-naphthols were efficiently synthesized in 36-92% yields.