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Cinchona alkaloids catalyze the enantioselective Mannich reaction of beta-keto esters with acyl aryl imines. The reaction requires 10 mol % of cinchonine or cinchonidine. The reaction products are obtained in good yields (81-99%), high enantioselectivities (80-96% ee), and in diastereoselectivities that range from 1:1 to >95:5. The cinchonine-catalyzed(More)
[reaction: see text] The cinchona alkaloids catalyze direct asymmetric Mannich reactions of cyclic 1,3-dicarbonyl compounds with acyl imines to afford alpha-quaternary carbon-bearing reaction products in yields of up to 98%, a diastereomeric excess of 90% or greater, and enantioselectivities up to 99% ee. A model is proposed that accounts for both the(More)
Chiral organic Brønsted bases have emerged as highly efficient catalysts for enantioselective transformations. Since their early use in enantiomeric separation processes, chiral organic Brønsted base catalysis has advanced significantly to include both natural and designed catalysts. Insight into the mode of action of the organocatalysts has promoted(More)
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