Cobalt‐Catalyzed Enantioselective Hydroboration/Cyclization of 1,7‐Enynes: Asymmetric Synthesis of Chiral Quinolinones Containing Quaternary Stereogenic Centers

An asymmetric cobalt‐catalyzed hydroboration/cyclization of 1,7‐enynes to synthesize chiral six‐membered N‐heterocyclic compounds was developed. A variety of aniline‐tethered 1,7‐enynes react with pinacolborane to afford the corresponding chiral boryl‐functionalized quinoline derivatives in high yields with high enantioselectivity. This cobalt‐catalyzed asymmetric cyclization of 1,7‐enyens provides a general approach to access a series of chiral quinoline derivatives containing quaternary stereocenters. Give me a ring: A highly enantioselective cobalt‐catalyzed hydroboration/cyclization of 1,7‐enynes with pinacolborane (HBpin) using a catalyst generated from Co(acac)2 and (S,S)‐Ph‐BPE was developed. This method provides a general approach to access a series of chiral quinoline derivatives containing quaternary stereocenters.