Organocatalytic enantioselective addition of 3-aryloxindoles to ethenesulfonyl fluoride

We report the synthesis of chiral sulfonyl fluorides bearing a carbon quaternary stereocenter. A commercially available organocatalyst (DHQD)2AQN enables the enantioselective addition of 3-substituted oxindoles to ethenesulfonyl fluoride (ESF), achieving excellent yields (27-99%) and enantioselectivities (89-99% ee) for 3-arylsubstituted oxindoles. This methodology shows high functional group tolerance, as demonstrated by successfully engaging halides, ethers, nitriles, acetals, ketals, or heteroaromatic substituents. The utility of the described products was proven by various synthetic transformations, including SuFEx reactions with complex biomolecules.