Chiral pyrrolidine–triazole conjugate catalyst for asymmetric Michael and Aldol reactions

A new pyrrolidine–triazole conjugate organocatalyst is synthesized using a Huisgen 1,3-dipolar cycloaddition reaction. The application of this catalyst in an asymmetric Michael addition and in an Aldol reaction is described, showing good catalytic activity. The reactions proceeded to give the products in good yield and in a highly selective manner.

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(S)-tert-Butyl 2-(1-benzyl-1H-1,2,3-triazol-4-yl) pyrrolidine-1-carboxylateC18H24N4O2[α]D25=-42.7 (c 0.8, CHCl3)Source of chirality: l-prolineAbsolute configuration: (2S)

(S)-1-Benzyl-4-(pyrolidin-2-yl)-1H-1,2,3-triazoleC13H16N4[α]D25=-15.0 (c 1.0, CHCl3)Source of chirality: l-prolineAbsolute configuration: (2S)

(S)-2-((R)-1-(2,5-Dimethoxyphenyl)-2-nitroethyl) cyclohexanoneC16H21NO5[α]D25=-25.1 (c 0.6, CHCl3)Source of chirality: Michael reactionAbsolute configuration: (2S,3R)

(S)-2-((R)-1-(2-Chloro-5-nitrophenyl)-2-nitroethyl) cyclohexanoneC14H15ClN2O5[α]D25=-8.0 (c 0.45, CHCl3)Source of chirality: Michael reactionAbsolute configuration: (2S,3R)

(S)-2-((R)-(Furan-3-yl)-2-nitroethyl) cyclohexanoneC12H15NO4[α]D25=-12.5 (c 0.75, CHCl3)Source of chirality: Michael reactionAbsolute configuration: (2S,3R)