Iridium‐Catalyzed Asymmetric Hydrogenation of 3‐Substituted 2<i>H</i>‐1,4‐Benzoxazines

Abstract

Abstract The highly enantioselective hydrogenation of 3‐aryl‐2 H ‐1,4‐benzoxazines was achieved using the (cyclooctadiene)iridium chloride dimer/( S )‐SegPhos/iodine {[Ir(COD)Cl] 2 /( S )‐SegPhos/I 2 } system as catalyst with up to 92% ee . The 3‐styryl‐2 H ‐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.