β-Carboxyphospholes via carboxylative desilylation: luminophores with a versatile connectivity attached

The synthesis of β-carboxyphospholes has been achieved via carboxylative desilylation of their β-TMS-substituted analogues in a CO₂ atmosphere. The title carboxylic acids allow facile transformation into the respective acyl chloride, carboxamide, ester and anhydride, which are compatible with bioconjugation, while the integrity of the phosphole unit is maintained.