Synthesis and highly enantioselective hydrogenation of exocyclic enamides:: (Z)-3-arylidene-4-acetyl-3,4-dihydro-2H-1,4-benzoxazines

Highly enantioselective hydrogenation of exocyclic enamides, (Z)-3-arylidene-4-acyl-3,4-dihydro-2H-benzoxazines, was achieved in up to 98.6% ee by using Rh/(R,R)-Me-Duphos complex as the catalytic system. The absolute configuration of the product was assigned as R by chemical interrelations.