Hydroxyphthalimide allied triazole-pyrrolidine catalyst for asymmetric Michael additions in water

A new hydroxyphthalimide-coupled triazole-pyrrolidine derivative has been synthesized and demonstrated as an efficient and stereoselective organocatalyst for the asymmetric Michael addition reaction of ketones to nitro olefins at room temperature. Good yields and high selectivities were achieved when benzoic acid was used in combination with organocatalyst 1, employing water as the reaction medium.

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(S)-tert-Butyl-2-((4-((1,3-dioxoisoindolin-2-yloxy)-1H-1,2,3-triazol-1-yl)methyl)pyrrolidine-1-carboxylateC21H25N5O5[α]D27=-39.6 (c 0.6, CHCl3)Source of chirality: l-prolineAbsolute configuration: (S)

(S)-2-((1-(Pyrrolidin-2-ylmethyl)-1H-1,2,3-triazol-4-yl)methoxy)isoindoline-1,3-dioneC16H17N5O3[α]D27=-18.4 (c 0.3, CHCl3)Source of chirality: l-prolineAbsolute configuration: (S)

(S)-2-((R)-2-Nitro-1-tolylethyl)cyclopentanoneC14H17NO3[α]D27=-12.8 (c 0.5, CHCl3)Source of chirality: Asymmetric Michael reactionAbsolute configuration: (2S,1R)