| Chiral aldehyde catalysis based on imine activation pricinple has gradually become a straightforward and highly efficient synthetic strategy for achieving asymmetric α-functionalization of primary amine compounds.To date,four chiral aldehyde catalyzed asymmetric α-functionalization reactions of amino acid derivatives,including an α-alkylation reaction,a Michaeladdition/cyclization reaction,a Mannich reaction and an α-allyl alkylation,have been successfully achieved.In this thesis,we employed this chiral aldehyde catalytic strategy in the asymmetric 1,6-conjugated addition of amino acid esters to para-quinone methide(p-QMs).Under the promotion of chiral aldehyde catalysts with different catalytic sites distribution,the anti-and syn-selective co-njugated additions are independently achieved in high efficiency.Two reasonable models are proposed by DFT calculation to explain the stereoselective control results.This thesis is divided into three chapters.In the first chapter,we summarized the research background of chiral aldehyde catalysis and the catalytic asymmetric 1,6-conjugated additi-on reaction of p-QMs.In chapter 2,we studied the chiral aldehyde catalyzed asymmetric 1,6-conjugated addition reaction of amino acid esters with p-QMs.We firstly explored the reaction conditions with the utilization of tert-butyl glycine and 4-benzylidene-2,6-di-tert-butylcyclohexa-2,5-dien-1-one as template reactants,including screening of chiral aldehyde catalysts,reaction solvents,bases,as well as the equivalents of the base and catalyst.Under the optimal conditions,we then examined the substrates scopes of para-QMs and amino acids.Finaly,two possible stereoselective control models were given by Density Functional Theory(DFT)calculations to illustrate the experimental results.In chapter 3,we described the experimental processes in detail.The characterization data of all new compounds and the X-ray data of compound 2.5g were provided. |
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