Research Projects

The reaction between enamines and alpha,beta-unsaturated carbonyl compounds known as Michael addition is a synthetically important C-C bond forming reaction which provides valuable 1,5-dicarbonyl compounds. This reaction involves direct C-C bond formation between soft nucleophilic and soft electrophilic centers of the reactants (soft-soft mode) with up to two new chiral centers. However, reactions of enamines with highly electrophilic alpha,beta-unsaturated metallocarbenes (vinylcarbenes) are challenging and remained unexplored. Since enamines offer both N-centered (hard) and C-centered (soft) nucleophilicity, we were interested in studying their reactivity with vinylcarbenoids which possess both hard (carbenoid) and soft (vinylogous) electrophilic centers. Unlike Michael reactions, controlling the chemoselectivity of this reaction might be challenging due to the competing hard-hard and soft-soft modes of reactivity. Herein, we propose the design of new class of metal bound protic N-allyl enammonium ylides from the chemoselective (hard-hard mode) reactivity of enamine with vinylcarbenoid and their stereoselective 3-aza-Cope reaction. This new C-C bond forming reaction would allow rapid construction of homoallylic imines with up to two contiguous stereocenters including valuable imine and (Z)-olefin motifs. Further, chiral amine and metal catalyzed direct catalytic enantioselective variation of this reaction will be developed to access (Z)-alpha,beta-unsaturated carbonyls. The rich chemistry of carbonyl and olefin allows further elaboration to diverse chiral building blocks having multiple stereocenters. The new methodologies would be used for the construction of chiral cyclic C/N/O compounds, natural products analogues for bioactivity studies and medicinal chemistry applications.