Ohishi et al. (from Hou group at Riken Research, Japan) reported facile CO2 activation by CuCl and N-heterocyclic carbene ligands. Organoboron complexes get the insertion of the CO2 and produce carboxylic acid counterpart by loosing the boron group. Their method is very efficient (over %90 conversion most cases) and the other functional groups on the structure seems little or not affected. The only downside is that you have to use little more than stochiometric (or in some cases twice as much) base (tBuOK) and similar amounts of acid (HCl) to get the reaction going.
Good job though.