Organocatalytic enantioselective decarboxylative reaction of malonic acid half thioesters with cyclic N-sulfonyl ketimines by using N-heteroarenesulfonyl cinchona alkaloid amides.

The organocatalytic enantioselective decarboxylative Mannich reaction of malonic acid half thioesters (MAHTs) with cyclic N-sulfonyl ketimines by using N-heteroarenesulfonyl cinchona alkaloid amides afforded products with high enantioselectivity. Both enantiomers of the products could be obtained by using pseudoenantiomeric chiral catalysts. The reaction proceeds through a nucleophilic addition of the MAHTs to the ketimines prior to decarboxylation.