Catalytic Lactonization of Unactivated Aryl C–H Bonds with CO2: Experimental and Computational Investigation

The first catalytic lactonization of unactivated aryl C–H bonds with CO 2 to afford important phthalides is reported. Notably, this method features high selectivity, excellent functional group tolerance, smooth scalability, and facile product diversification. DFT calculations reveal that a novel insertion of two CO 2 into the O–Pd bond of a palladacycle might be the key step, providing great potential and a different perspective for carbonylation with CO 2 .