Dynamic Kinetic Resolution Reactions Of Azlactones Catalyzed By Organocatalysts

1. Research on Organocatalyzed Reactions1) DKR Reactions of Azlactones Catalyzed by OrganocatalystsFive azlactones 3a-3e were synthesized. Primary studies on the dynamic kinetic resolution reactions of azlactones have been tried using organocatalysts 4-7, synthesized in our group: Asymmetric reaction of 2-phenyl-4-benzyloxazolone with allyl alcohol in the presence of chiral organocatalyst was realized affording the corresponding ring-opening product of 9% ee.2) Aldol Reactions Catalyzed by OrganocatalystsCompounds 12a-12f were tested as catalysts for the asymmetric aldol reaction of activated ketones (with electron-withdrawing group in a-position) and 9(with electron-withdrawing group in β-position), up to 95% yield and 27% ee was achieved.2. Organocatalyzed Reactions of Carbonyl Compounds with Organometallic Reagents1) Enantioselective Addition of Diethylzinc to Substrate 9Enantioselective addition of diethylzinc to 9 have been tried in the presence of 21.2) Asymmetric Addition of Tetraallyltin towards Aromatic AldehydesThe asymmetric addition of Tetraallyltin to aromatic aldehydes was achieved by using N-aclylated Z,-aspartic acids as promoters. Optically active homoallylic alcohols were obtained in high yields with enantiomeric excess up to 27%. The absolute configuration of the product was found opposite to that promoted by Z,-aspartic acid.