3,6-DEDEOXY-3,6-IMINOFURANOSIDE DERIVATIVES AS ORGANOCATALYSTS FOR THE ASYMMETRIC MICHAEL ADDITION

摘要

Asymmetric reactions using organocatalysts have become one of the most active and growing fields of research on catalytic asymmetric reactions, and also have become a powerful tool for performing stereoselective transformations that were classically achieved using transition metal or enzymatic catalysts. In the field of carbohydrate chemistry, various kinds of organocatalysts have been synthesized for asymmetric carbon-carbon bond formation. For example, Machinami's group reported an aldol reaction in aqueous media catalyzed by methyl 2-(L-prolyl)amido-2-deoxy-α-D-glucopyranosides. Peddinti's group also reported an Michael reaction in solvent-free conditions catalyzed by sugar-based prolinamides. Therefore, we thought that 3,6-dideoxy-3,6-iminocarbohydrates served as an organocatalyst for the asymmetric reaction because the derivatives have pyrrolidine moiety on the furanosidic ring. We would like to report this time an asymmetric Michael addition of cyclohexanone to nitroolefin using 3,6-dideoxy-3,6-iminocarbohydrates as a new organocatalyst.