Journal of the American Chemical Society 2006-07-05

Highly enantioselective azadiene Diels-Alder reactions catalyzed by chiral N-heterocyclic carbenes.

Ming He, Justin R Struble, Jeffrey W Bode

Index: J. Am. Chem. Soc. 128 , 8418, (2006)

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Abstract

Highly enantioselective, N-heterocyclic carbene (NHC)-catalyzed aza-Diels-Alder reactions are described. A novel chiral triazolium salt based on the cis-1,2-aminoindanol platform serves as an efficient precatalyst for the NHC-catalyzed redox generation of enolate dienophiles that undergo LUMOdiene-controlled Diels-Alder reactions with N-sulfonyl-alpha,beta-unsaturated imines in good yields and with exceptional diastereo- and enantioselectivities (>99% ee). In contrast to uncatalyzed variants, this organocatalytic process proceeds at room temperature without stoichiometric reagents, producing synthetically valuable, enantiomerically pure cis-3,4-disubstituted dihydropyridinone products.