A new visible-light-driven method for the carboxylation
of (hetero)aryl/vinyl
bromides has been developed using catalytic 4CzIPN, nickel, phenyl
triflimide, and sodium formate as a carboxylation agent. Interestingly,
we found catalytic phenyl triflimide plays an essential role in promoting
the reaction. While many C(sp2) carboxylation reactions
require harsh reagents or gaseous carbon dioxide, we demonstrate the
mild and facile construction of carboxylic acids from readily available
starting materials.