Ruthenium-catalysed late-stage C–H alkynylation of carboxylic acids using sustainable deep eutectic solvents†

The demand for sustainable and environmentally friendly chemical processes has led to the development of innovative catalytic systems and solvent designs. Herein, we report a novel approach utilizing ruthenium catalysis in deep eutectic solvents (DESs) for the selective alkynylation of C–H bonds. Ruthenium, known for its low toxicity and cost-effectiveness, serves as an excellent alternative to other transition metals in eutectic liquids. Moreover, the utilization of supramolecular β-cyclodextrin-based deep eutectic liquids enhances the eco-friendliness and recoverability of the solvent system. The late-stage functionalization of drugs exemplifies the practical applicability and versatility of this method in organic synthesis, offering a sustainable pathway towards the synthesis of valuable compounds.