Asymmetric Nitro-Mannich Reaction Of N-phosphoryl Imines And Asymmetric Michael Addition Reaction Of4-Oxo-enoates

Reactions that utilize addition of active C-H nucleophiles to C=X bonds represent one of the most fundamental carbon-carbon bond-forming processes in organic chemistry. The nitro-Mannich reaction and Michael addition reaction are typical of this family of carbon-carbon bond-forming reactions. Although these reactions have been known for a century, the studies of the asymmetric nitro-Mannich reaction and Michael addition reaction are still very active fields of organic synthesis research.This dissertation includes three parts:(1) In the first part of the dissertation, the recent progresses on the asymmetric nitro-Mannich reactions have been reviewed. Using different kinds of catalysts to asymmetric catalyze the reactions of nitroalkanes and imines have also been reviewed.(2) We carried out the asymmetric nitro-Mannich reaction between a-substituted nitroacetates and N-phosphoryl imines to obtain the corresponding β-nitro ethylphosphoramidates derivatives with adjacent quaternary and tertiary chiral centers. The reaction was performed by using chiral bifunctional tertiary amine-thiourea as catalyst in toluene as solvent at-20℃. To our delight, products can be obtained with high yields (up to86%) and high enantiostereoselectivities (up to99%ee) and diastereoselectivities (up to99:1, anti-selective). The structure was confirmed by X-ray diffraction analysis and the structure showed that the absolute configuration of the β-nitro ethylphosphoramidates product was assigned as (S,S). The compounds’ structures were confirmed by1H NMR,13C NMR,31P NMR, ESI-MS and ESI-HRMS.(3) We studied the enantioselective Michael addition reaction of a-substituted nitroacetates with4-oxo-enoates to produce active y-keto esters. The reaction was performed by using chiral bifunctional tertiary amine-thiourea as catalyst in toluene as solvent at0℃and resulted into β-amino acids in high yields with high enantiostereoselectivities and diastereoselectivities. The structure was confirmed by X-ray diffraction analysis and the structure showed that the absolute configuration of the γ-keto esters product was assigned as (S,S). The compounds’structures were confirmed by1H NMR,13C NMR,31P NMR, ESI-MS and ESI-HRMS.