Cu-Catalysed carboxylation of aryl boronic acids with CO2†
A copper/N-heterocyclic carbene (NHC) catalysed carboxylation of aryl boronic acids under one atmospheric pressure of CO2 has been developed. A wide range of aryl boronic acids was transformed into benzoic acid derivatives in moderate to high yields. The carboxylation method shows excellent functional group compatibility, and sensitive functional groups such as carbonyls, esters, and nitriles were tolerated. Mechanistic studies revealed the vital role of the base in promoting the transmetalation step for this copper-catalysed carboxylation.