Scheme 2.

Ligand Effect on Co(II)-Based Asymmetric System for Intermolecular C–H Amination with Organic Azides^a

^aCarried out with 1 (0.10 mmol) and 2a (0.15 mmol) in the presence of 4 Å molecular sieves by [Co(Por*)] (4 mol %) in trifluorotoluene (0.5 mL) at 40 °C for 48 h. Isolated yields. Enantiomeric excess was determined by chiral HPLC. ^bStructure of P6 was determined by X-ray crystallography.