Catalytic Asymmetric Reaction with Water: Enantioselective Synthesis of α‐Hydroxyesters by a Copper–Carbenoid OH Insertion Reaction

Taking on water: A novel catalytic asymmetric metal–carbenoid insertion reaction with water has been developed with copper complexes of chiral spiro bisoxazoline ligands as catalysts. This reaction provides an efficient and practical procedure for preparing chiral α-hydroxyesters and acids starting from readily available materials in high yields and enantioselectivities. BArF−=[B{3,5-(CF3)2C6H3)}4]−.