Enantioselective Stetter Reactions Catalyzed by Bis(amino)cyclopropenylidenes: Important Role for Water as an Additive
Mehran Rezazadeh Khalkhali, Myron M. D. Wilde, Michel Gravel
Abstract
The first highly enantioselective intermolecular Stetter reaction using simple enones is reported. A series of novel chiral BAC structures were designed and prepared. They were tested in the Stetter reaction with simple aldehydes and enones. The products were generated in excellent yields and enantioselectivities (up to 94% ee). Surprisingly, a substoichiometric amount of water was crucial to obtain high enantioselectivities. Chiral BACs were also shown to catalyze 1,6-conjugate addition reactions with paraquinone methides enantioselectively.
Topics & Concepts
Enantioselective synthesisChemistryCatalysisConjugateIntermolecular forceOrganic chemistryOrganocatalysisReaction conditionsCombinatorial chemistryMoleculeMathematical analysisMathematicsN-Heterocyclic Carbenes in Organic and Inorganic ChemistrySynthetic Organic Chemistry MethodsAsymmetric Hydrogenation and Catalysis