Enantioselective 1,4‐Addition Reaction of α,β‐Unsaturated Carboxylic Acids with Cycloalkanones Using Cooperative Chiral Amine–Boronic Acid Catalysts
Takahiro Horibe, Takashi Hazeyama, Yuto Nakata, Kazuki Takeda, Kazuaki Ishihara
Abstract
An enantioselective 1,4-addition of α,β-unsaturated carboxylic acids with cycloalkanones has been developed by using chiral amine-boronic acid cooperative catalysts. In the presence of a chiral amine and boronic acid, cycloalkanones and carboxylic acids are activated as chiral enamines and mixed anhydrides, respectively. The corresponding 1,4-adducts are obtained in high yield with high enantioselectivity. Furthermore, subsequent oxylactonization of the 1,4-adducts gives spirolactones with high diastereoselectivity.
Topics & Concepts
Enantioselective synthesisBoronic acidChemistryAmine gas treatingCatalysisAdductOrganic chemistryYield (engineering)Carboxylic acidMaterials scienceMetallurgyAsymmetric Synthesis and CatalysisSynthetic Organic Chemistry MethodsOxidative Organic Chemistry Reactions