Kinetic Resolution of Sulfoximines via Asymmetric Organocatalyzed Formation of Benzothiadiazine-1-oxides.

A catalytic kinetic resolution of sulfoximines has been developed through chiral phosphoric acid-catalyzed intramolecular dehydrative cyclizations. A variety of racemic sulfoximines bearing an ortho -amidophenyl moiety underwent asymmetric dehydrative cyclizations using this method, yielding both the recovered sulfoximines and benzothiadiazine-1-oxide products with good to high enantioselectivities (with s -factor up to 61). The diverse derivatizations of the chiral products into a wide range of S-stereogenic center-containing S,N-heterocycles have demonstrated the value of this method.