Copper-catalyzed arylation of indolin-2,3-ones with arylboronic acids

A convenient and efficient Cu(OTf)2-catalyzed arylation of indolin-2,3-ones with arylboronic acids using cheap 1,10-phenanthroline hydrate as ligand was developed under air atmosphere, achieving 3-aryl-3-hydroxy-2-oxindoles in good to excellent yields. This catalytic system shows broad functional group tolerance. Moreover, the rigorous exclusion of air/moisture is not required in these transformations.