Enantioselective construction of quaternary stereocenters via organocatalytic arylation of isoxazolin-5-ones with o-quinone diimides

A bifunctional squaramide derived from Cinchona alkaloid catalyzes the enantioselective arylation of isoxazolin-5-ones with o-quinone diimides (o-QDIs) to give isoxazolin-5-ones featuring an arylated quaternary stereocenter in high yields and excellent enantioselectivities. To the best of our knowledge, this is the first reported enantioselective arylation of isoxazol-5-ones and the first application of o-QDIs as arylating reagents in asymmetric catalysis.