Organophotoredox-Catalyzed C-H Functionalizations of Benzophospholes.

An organophotoredox-catalyzed oxidative C-H functionalization of benzophospholes has been developed. The C-H alkoxycarbonylation with methyl carbazate occurs in the presence of Rose bengal, whereas Eosin Y enables the dehydrogenative coupling with secondary phosphine oxides and ethers, delivering the C-H phosphinylated and alkylated products. The scope of coupling partners is complementary to that of conventional metal-promoted C-H activation, thus successfully expanding the chemical space of substituted phospholes accessed by C-H functionalization protocols.