Quinine-Catalyzed Asymmetric Synthesis of 2,2’-Binaphthol-Type Biaryls under Mild Reaction Conditions

摘要

Simple quinine as an organocatalyst mediates theudaddition of various naphthols to halogenated quinones toudafford non-C2-symmetrical, axially chiral biaryl products,udwhich are promising compounds as chiral ligands and organocatalysts.udThe rotational barrier required to have two distinctudatropisomers has been evaluated in the products generatedudfrom the addition of naphthols to various quinones by meansudof DFT calculations and HPLC. The use of halogenatedudquinones as reagents was necessary to have configurationallyudstable enantiomeric products which can be obtained in goodudyield and stereoselectivity. These compounds have also beenudprepared in gram quantities and recrystallized to near enantiopurity.