Regioselective Direct C2 Arylation of Indole, Benzothiophene and Benzofuran: Utilization of Reusable Pd NPs and NHC-Pd@MNPs Catalyst for C-H Activation Reaction

A regioselective C2 arylation of indoles, benzothiophene and benzofuran without directing group has been accomplished using economically cheap Pd NPs and NHC-Pd@MNPs catalyst. The reusable catalyst is efficiently employed to access C2 arylated heterocycles in good to excellent yield. The reusability of the catalyst is studied up to five cycles and a gram-scale synthesis has been achieved. The reaction mechanism is well supported by control experiments and literature precedents. [GRAPHICS] .

Automated summary

This study achieved regioselective C2 arylation of indoles, benzothiophene, and benzofuran without directing group using affordable Pd NPs and NHC-Pd@MNPs catalyst. The reusable catalyst efficiently produced C2 arylated heterocycles in good to excellent yield, with potential for gram-scale synthesis. The reaction mechanism was supported by control experiments and literature precedents.