Enantioselective Squaramide-Catalysed Domino Mannich–Cyclization Reaction of Isatin Imines

摘要

An enantioselective domino reaction of 4-bromo-3-oxobutanoates with isatin-derived ketimines was developed to construct 3-amino-2-oxindoles with a quaternary stereocentre. In the presence of 1 mol-% of a bifunctional squaramide or-ganocatalyst, the desired products were achieved in high yields (90–97%) and with excellent enantioselectivities (92– 99% ee).