Iridium‐Catalyzed Asymmetric Hydrogenation of 3‐Substituted 2H‐1,4‐Benzoxazines

The highly enantioselective hydrogenation of 3‐aryl‐2H‐1,4‐benzoxazines was achieved using the (cyclooctadiene)iridium chloride dimer/(S)‐SegPhos/iodine {[Ir(COD)Cl]2/(S)‐SegPhos/I2} system as catalyst with up to 92% ee. The 3‐styryl‐2H‐1,4‐benzoxazine derivatives were also hydrogenated by the iridium catalyst and Pd/C in two consecutive steps whereby 93–95% ee values were obtained.