Asymmetric Mannich reactions of beta-keto esters with acyl imines catalyzed by cinchona alkaloids.
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 reaction provides access to highly functionalized building blocks used in the asymmetric synthesis of a dihydropyrimidone and beta-amino alcohol.
Lou
Sha
S
Department of Chemistry and Center for Chemical Methodology and Library Development, Life Science and Engineering Building, Boston University, 24 Cummington Street, Boston, Massachusetts 02215, USA.
Taoka
Brandon M
BM
Ting
Amal
A
Schaus
Scott E
SE
D002384:Catalysis; D002930:Cinchona Alkaloids / Q000737:chemistry*; D004952:Esters / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D008352:Mannich Bases / Q000737:chemistry
D002930:Cinchona Alkaloids; D004952:Esters; D007097:Imines; D007659:Ketones; D008352:Mannich Bases