Lewis Acid-Catalyzed Friedel-Crafts Reaction Of Styrene Derivatives

In recent years,asymmetric Friedel-Crafts alkylation of aromatic compounds has been intensely developed,which provides efficient access to optically active aromatic derivatives.Allylic alcohol is an important structural unit of natural products.The synthesis of allylic alcohol has received considerable attention and a number of efficient methods have been developed.Among them,the Friedel-Crafts alkylation of alkenes represents a direct and convenient synthetic method to allylic alcohol.However,Friedel-Crafts alkylation of simple alkenes even in its racemic version is far away from success.In this dissertation,Friedel-Crafts alkylation reaction of styrenes with trifluoropyruvates has been developed.1.The alkylation reaction of styrenes with keto esters was studied,which delivered allylic alcohols.The optimal reaction conditions were found after the scanning of Lewis acid,solvent,ligand and so on.With 10 mol%of Ni-2,2'-bpy complex,the reaction proceeds efficiently in DCM at 100 ? and allylic alcohols were obtained from 40%to 98%yield.2.The enantioselective alkylation reaction of styrenes with trifluoropyruvates was studied,which delivered chiral allylic alcohols.The optimal reaction conditions were found after the scanning of chiral ligand,Lewis acid,solvent,temperature and so on.With 10 mol%of Cu-bisoxazoline complex,the reaction proceeds efficiently in CHCl₃ at 100?,giving the yield from 28%to 88%and the enantioselectivity from64%to 75%.