Parallel Kinetic Resolution through Palladium-Catalyzed Enantioselective Cycloimidoylation: En Route to Divergent N-Heterocycles Bearing a Quaternary Stereogenic Center

An example of a parallel kinetic resolution catalyzed by palladium to produce enantioenriched five- and six-membered N-heterocycles in one pot was developed. Dihydroisoquinolines and 1H-isoindoles containing a quaternary stereogenic center were obtained from racemic isocyanides in high yields with good enantioselectivities under mild conditions. A 6,6'-dipropyl substituted SPINOL-derived phosphoramidite was used as the chiral ligand for the palladium catalyst, resulting in regiodivergent and stereospecific cycloimidoylation. Density functional theory (DFT) calculations reveal the origin of the regio- and enantioselectivity during the C(sp(2))-H imidoylative cyclization process.