Abstract
In this work, three forms of a novel octapeptide have been evaluated as asymmetric catalysts for the Michael reaction. Low quantity catalyst loading, ecofriendly solvents, and reusability of organocatalyst successfully applied to attain excellent yields and moderate enantioselectivities in the Michael reaction.
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resources: Full experimental and spectral details.]
GRAPHICAL ABSTRACT
Notes
a Reaction were performed with aldehydes or ketones (2eq) and nitroolefins (1eq), solvents (0.5 ml:0.5 ml), NMM (1 drop to adjust pH = 5–5.5), at RT.
b Isolated yield of mixture of syn/anti based on nitrostyrene. Diastereomeric ratio, determined by 1H NMR.
c Enantiomeric excess, determined by chiral-phase HPLC analysis.
d Diisopropylethylamine (to adjust pH = 5–5.5).