Cobalt‐Catalyzed Asymmetric Aza‐Nozaki‐Hiyama‐Kishi (NHK) Reaction of α‐Imino Esters with Alkenyl Halides

Chromium‐catalyzed enantioselective Nozaki−Hiyama−Kishi (NHK) reaction represents one of the most powerful approaches for the formation of chiral carbon‐heteroatom bond. However, the construction of sterically encumbered tetrasubstituted stereocenter through NHK reaction still posts a significant challenge. Herein, we disclose a cobalt‐catalyzed aza‐NHK reaction of ketimine with alkenyl halide to provide a convenient synthetic approach for the manufacture of enantioenriched tetrasubstituted α‐vinylic amino acid. This protocol exhibits excellent functional group tolerance with excellent 99% ee in most cases. Additionally, this asymmetric reductive method is also applicable to the aldimine to access the trisubstituted stereogenic centers.