Organocatalytic Synthesis Of Heterocyclic Compounds

This thesis is mainly composed of three parts: 1 、 Enantioselective organocatalytic 1,6-addition of azlactones to para-Quinone MethidesThis work describes the first enantioselective 1,6-additions of azlactones to para-quinone methides.In the presence of a chiral phosphoric acid,1,6-adducts were obtained in high yields(up to 96%)with excellent diastereoselectivities and enantioselectivities(all >20:1 diastereoselectivity ratio(dr),up to 99% enantiomeric excess(ee)).Importantly,the method offers a facile synthetic approach,not only to enantiopure α,α-disubstituted α-amino acid esters,but also to unnatural enantioenriched β,β-diaryl-α-amino acid esters bearing adjacent tertiary and quaternary stereogenic centers.2、Organocatalytic 1,6-addition of phosphorus phenoxide to para-Quinone MethidesWe have developed the asymmetric 1,6-conjugated addition reaction of para-Quinone Methides with phosphorus phenoxide by chiral amine catalysts.Multiple substituted chiral phosphorus derivatives containing P-C bonds were synthesized with high yields and high enantioselectivities.3、Organocatalytic 1,3-dipolar cycloaddition reaction of 1,2-cyclohexanedione with azidesEnamine-mediated 1,3-dipolar cycloaddition reactions of 1,2-cyclohexanedione with azides have been developed.This strategy could generate highly substituted 1,2,3-triazoles in high yields and high levels of regioselectivities.It has been demonstrated that various types of products could be obtained using different organocatalysts and substrates.