Enantioselective Synthesis of 4‐Substituted Dihydrocoumarins through a Zinc Bis(hydroxyamide)‐Catalyzed Conjugate Addition of Terminal Alkynes

Abstract A new enantioselective catalyst for the conjugate addition of terminal alkynes has been developed. Terminal alkynes react with 3‐alkoxycarbonylcoumarins in the presence of diethylzinc and bis(hydroxyamide) ligands to give chiral non‐racemic dihydrocoumarins substituted with an alkynyl group on the C‐4 position with good yields and enantiomeric excesses up to 95%.