Sequential coupling/desilylation–coupling/cyclization in a single pot under Pd/C–Cu catalysis: Synthesis of 2-(hetero)aryl indoles

Abstract

A new one-pot synthesis of 2-(hetero)aryl indolesvia sequential C–C coupling followed by C–Si bond cleavage and a subsequent tandem C–C/C–N bond forming reaction is described. A variety of functionalized indole derivatives were prepared by conducting this four step reaction under Pd/C–Cu catalysis. The methodology involved coupling of (trimethylsilyl)acetylene with iodoarenes in the presence of 10% Pd/C–CuI–PPh₃ and triethylamine in MeOH, followed by treating the reaction mixture with K₂CO₃ in aqueous MeOH, and finally coupling with o-iodoanilides. The single crystal X-ray data of a synthesized indole derivative is presented. Application of the methodology, in vitro pharmacological properties of the synthesized compound, along with a docking study is described.