Cinchona Alkaloid-Derived Thioureα-Catalyzed Diastereo-and Enantioselective [3+2] Cycloaddition Reaction of Isocyanoacetates to Isatins: A Facile Access to Optically Active Spirooxindole Oxazolines

摘要

An efficient diastereo- and enantioselective [3+2] cycloaddition reaction of α-aryl isocyanoacetates to isatins catalyzed by a quinine-derived bifunctional amine-thioureα-bearing sulfonamide as multiple hydrogen-bonding donor catalyst has been investigated. The corresponding adducts, which bear a spirocyclic quaternary stereocenter at the C-3 position of the oxindole, were obtained in good yields (51-95%), high diastereoselectivities (up to >20:1 dr) and good to excellent enantioselectivities (up to 97% ee).