Photoredox/Palladium Dual Catalysis for Site-Selective C-H Arylation and Acylation of N -Protected Carbazoles in Visible Light.

An unprecedented C-1 selective mono-arylation/acylation of N -protected carbazoles with aryl diazonium salts/glyoxylic acids has been developed in visible light by dual catalytic system comprising of Eosin Y and palladium acetate. The methodology has good functional group tolerance and high regioselectivity and furnishes the monosubstituted products in moderate to good yields at room temperature.