Organocatalytic Asymmetric Michael Addition And Michael-Cyclization Domino Reaction Of Electron-Deficient Olefins

1. The synthesis of chiral catalystsAs biological catalysis and metal catalysis, organocatalysis is another important class of asymmetric catalysis. For its merits of metal-free, mild reaction condition, easily operation and economical efficiency, many chemists put their eyes on this resesrch area. According to the methods from the literatures, some bifunctional cinchona alkaloid derivatives catalysts were synthesised and then employed into some asymmetric Michael addition initiated reactions.2. Investigation on the Asymmetric Michael Addition of Azlactones to o-Hydroxy Chalcone DerivativesOur study disclosed that the enantioselective C-2 additions of phenylglycine derivatives azlactones to o-hydroxy chalcone derivatives were successfully realized by organocatalysis. This reaction was launched by the C-2 site of this kind of azlactones. The bifunctional cinchona alkaloid derivatives quinine thiourea catalyst exhibited outstanding catalytic efficiency for the C-2 additions of azlactones to o-hydroxy chalcone derivatives, providing N,O-aminals derivatives with two continuous stereogenic centers in moderate to good yields(54–99%), excellent diastereoselectivities(>20/1) and good to excellent enantioselectivities(72–99%). The resultant N,O-aminals derivatives are highly important for the synthesis of related natural products and pharmaceutically active compounds.3. Investigation on the Asymmetric Michael/Ring-Opening Domino Reaction of Azlactones and o-Hydroxy Chalcone DerivativesOptical chroman-2-one derivatives could be obtained through the asymmetric Michael/ring-opening domino reaction of azlactones and o-hydroxy chalcone derivatives catalyzed by the Bifunctional Cinchona Alkaloid derivatives quinine thiourea catalyst. The chroman-2-one derivatives could be obtained in moderate to excellent yields(64–99%), excellent diastereoselectivities(>20/1) and good to excellent enantioselectivities(84–99%). This method is simplicity, high efficiency and good functional group compatibility.4. Investigation on the Organocatalytic Domino Michael-Cyclization of Isatin Derived β, γ-Unsaturated a-Keto Esters with 2-Hydroxy-1,4-NaphthoquinoneThe enantioselective domino Michael cyclization of isatin derived β, γ-unsaturated a-keto esters with 2-hydroxy-1,4-naphthoquinone were successfully realized by organocatalysis. The motif of the resultant products is highly important for the synthesis of related natural products and pharmaceutically active compounds. The bifunctional cinchona alkaloid derivatives para-nitro hydroquinine thiourea catalyst exhibited outstanding catalytic efficiency for the organocatalytic Michael domino cyclization of isatin derived β, γ-unsaturated a-keto esters with 2-hydroxy-1,4-naphthoquinone. Through this way, the spirooxindoles derivatives could be obtained in moderate to good yields(52–92%), excellent diastereoselectivities(>20/1) and excellent enantioselectivities(93–99%).