Visible-Light-Induced Direct Photocatalytic Carboxylation of Indoles with CBr4 /MeOH.

Photocatalysis enables the cascade reactions of indoles and CBr4 in MeOH through a C(sp(2) )H functionalization/methanolysis sequence. The title reaction provides an efficient access to indole 2- and 3-carboxylates in a single operation (no preinstallation of protecting as well as directing groups was required) with good yields under mild reaction conditions.