Acrylic acid derivatives as Michael acceptors

When acrylates or related compounds are employed as electrophiles in conjugate addition reactions, a conveniently substituted C-H pro-nucleophile has to be employed in order to generate a new stereogenic center. For this reason, most of the methodologies reported in this context involve the use of 2-sub-stituted 1,3-dicarbonyl compounds or related derivatives as Michael donors. 

Moreover, as is usually found in most of the asymmetric reactions catalyzed by cinchona alkaloid derivatives, the opposite enantiomer of each diaster-eomeric Michael adduct could also be obtained by simply changing the catalyst to the corresponding pseudoenantiomeric quinidine-based compounds of type 83 or 71. Once again, a model was proposed to account for the observed results, involving a conformationally rigid intermediate in which both the pronucleophile and the electrophile were attached to the catalyst by the formation of multiple H-bonds, explaining the reversal of the diastereoselection by the epimeric nature of C-9 in catalyst 71b with respect to 84c. The stereochemical 

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