Black phosphorus as a metal-free, visible-light-active heterogeneous photoredox catalyst for the direct C–H arylation of heteroarenes

Black phosphorus (BP) is for the first time employed as a metal-free, heterogeneous photoredox catalyst for the direct C-H arylation of heteroarenes with aryl diazonium salts. The arylated heteroarenes are obtained in moderate to good yields under visible-light illumination, and the protocol is shown to be applicable for the scale-up synthesis.