Photoinduced Copper-Catalyzed Regioselective Synthesis of Indoles: Three-Component Coupling of Arylamines, Terminal Alkynes, and Quinones

The first successful example of a visible-light-induced copper-catalyzed process for CH annulation of arylamines with terminal alkynes and benzoquinone is described. This three-component reaction allows use of a variety of commercial terminal alkynes as coupling partners for the one-step regioselective synthesis of functionalized indoles. Moreover, the current process represents a sustainable and atom-economical approach for the preparation of complex indoles from easily accessible starting materials under visible-light irradiation, without the need for expensive metals and harsh reaction conditions.