Chiral Binaphthol-Catalyzed Enantioselective Conjugate Addition of Alkynyl Trifluoroborates to α,β-Unsaturated Cyclic N-Sulfonyl Ketimines

J Org Chem. 2025 Jun 27. doi: 10.1021/acs.joc.5c00945. Online ahead of print.

Abstract

The chiral binaphthol-catalyzed enantioselective conjugate addition of alkynyl trifluoroborates to cyclic N-sulfonyl ketimines is reported, providing β-alkynyl imines bearing a propargylic stereocenter in high yields and excellent enantiomeric purities (up to >99% ee). This mild, scalable catalytic system exhibits high efficiency and broad substrate scope. Additionally, heteroaryl trifluoroborates and aryl trifluoroborates were viable nucleophiles under standard conditions.