Enantioselective Alkynylation of Unstabilized Cyclic Iminium Ions
Weiye Guan, Samantha O. Santana, Jennie Liao, Kelci Henninger, Mary P. Watson
Abstract
An enantioselective copper-catalyzed alkynylation of unstabilized cyclic iminium ions has been developed. Whereas such alkynylations typically utilize pyridinium, quinolinium, and isoquinolinium intermediates, this method enables use of cyclic iminium ions unstabilized by resonance. With the use of a Lewis acid and copper catalyst, these iminium ions are generated in situ from readily available hemiaminal methyl ethers and transformed into highly enantioenriched α-alkynylated cyclic amines. A variety of terminal alkynes can be incorporated in high yields and enantiomeric excesses.
Topics & Concepts
IminiumEnantioselective synthesisAlkynylationChemistryCatalysisIonCombinatorial chemistryOrganic chemistryCatalytic C–H Functionalization MethodsAsymmetric Synthesis and CatalysisSynthesis and Catalytic Reactions