Sugar amide-pyrrolidine catalyst for the asymmetric Michael addition of ketones to nitroolefins

New sugar amide-pyrrolidine derivatives possessing the furano form of the carbohydrate template were designed and developed as efficient and stereoselective organocatalysts for asymmetric Michael additions of ketones to nitroolefins at room temperature. Good yields and high selectivities were achieved with catalyst 2 under solvent-free and additive-free reaction conditions.

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(3aR,5S,6R,6aR)-6-Amino-2,2-dimethyl-N-((S)-pyrrolidin-2-lmethyl)tetrahydrofuro[2,3-d][1,3]dioxole-5-carboxamideC13H23N3O4[α]D25=-39.6 (c 1.4, CHCl3)Source of chirality: l-proline, d-glucoseAbsolute configuration: (3aR,5S,6R,6aR)-(S)

(3aR,5S,6R,6aR)-6-Hydroxy-2,2-dimethyl-N-((S)-pyrrolidin-2-ylmethyl)tetrahydrofuro[2,3-d][1,3]dioxole-5-carboxamideC13H22N2O5[α]D25=-33.2 (c 1.1, CHCl3)Source of chirality: l-proline, d-glucoseAbsolute configuration: (3aR,5S,6R,6aR)-(S)

(S)-Benzyl 2-(((3aR,5S,6R,6aR)-6-azido-2,2-dimethyltetrahydrofuro[2,3-d][1,3]dioxole-5-carboxamido)methyl)pyrrolidine-1-carboxylateC21H27N5O6[α]D25=-42.8 (c 0.25, CHCl3)Source of chirality: l-proline, d-glucoseAbsolute configuration: (S)-(3aR,5S,6R,6aR)

(S)-Benzyl 2-(((3aR,5S,6R,6aR)-6-(benzyloxy)-2,2-dimethyltetrahydrofuro[2,3-d][1,3]dioxole-5-carboxamido)methyl)pyrrolidine-1-carboxylateC28H34N2O7[α]D25=-31.6 (c 0.2, CHCl3)Source of chirality: l-proline, d-glucoseAbsolute configuration: (S)-(3aR,5S,6R,6aR)