Asymmetric Synthesis of Hydroquinazolines Bearing C4-Tetrasubstituted Stereocenters via Kinetic Resolution of α‑Tertiary Amines

A novel protocol for asymmetric synthesis of hydroquinazolines bearing C4-tetrasubstituted stereocenters has been achieved through kinetic resolution of 2-amido α-tertiary benzylamines via chiral phosphoric acid catalyzed intramolecular dehydrative cyclizations. This method gave access to both α-tertiary benzylamines and hydroquinazolines with broad scope and high enantioselectivities. An intriguing restricted rotation of the C–N bond was observed for hydroquinazoline products bearing C4-tetrasubstituted stereocenters

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