Chiral Silver Alkoxide Catalyzed Asymmetric Mannich-Type Reaction of Alkenyl Esters with Isatin Imines

Abstract A catalytic enantioselective Mannich-type reaction of alkenyl esters with isatin imines was achieved by using a Tol-BINAP·AgSbF6 complex as the chiral precatalyst and N,N-diisopropylethylamine as the base precatalyst in the presence of methanol. Optically active 3-alkylated 3-amino-2-oxindoles having up to 98% ee were diastereoselectively obtained in moderate to high yields not only from acyclic alkenyl esters but also from cyclic esters through the in situ generated chiral silver enolates.