- Preparation method of chiral 4 - aryl - β β-amino acid derivative
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Provided is a method for preparing a chiral 4-aryl-β-amino acid derivative. The preparation method comprises hydrogenating an enamine compound having a structure as shown in Formula III in an organic solvent in the presence of a catalyst containing a transition metal and BIBOPs. The preparation method of the present invention uses a small amount of a selected asymmetric catalyst, and has a simple operation, mild reaction conditions, a high yield, a high stereoselectivity, and better industrial application and economic values.
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- Recycling method of acetyl Meldrum's acid derivative degradation waste
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The invention provides a recycling method of acetyl Meldrum's acid derivative degradation waste, and belongs to the technical field of resource reutilization. According to the method disclosed by the invention, acetyl Meldrum's acid derivative degradation waste is subjected to preheating treatment, alcoholysis reaction, ammonolysis reaction, acetylation reaction and purification treatment, the main components in theacetyl Meldrum's acid derivative degradation waste are converted, and a recovery product is finally obtained and can be used as an important intermediate in a sitagliptin production process, so that waste resource reutilization in the production process of the sitagliptin bulk drug is realized, economic loss caused by degradation of the acetyl Meldrum's acid derivative in the production process of the sitagliptin bulk drug is reduced, the problem of environmental pollution caused by degradation of the acetyl Meldrum's acid derivative in the production process of the sitagliptin bulk drug is eliminated, and the sustainable development of a sitagliptin raw material medicine green pharmaceutical process is promoted.
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Paragraph 0056-0061; 0065-0067
(2021/07/01)
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- Highly efficient and facile synthesis of β-enaminones catalyzed by diphenylammonium triflate
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Abstract: The catalytic performance of diphenylammonium triflates as an organocatalyst in the synthesis of β-enaminones from various substituted β-diketones and amides (or amines) were evaluated. A wide range of β-enaminones were efficiently synthesized in good to excellent yields under mild reaction conditions. Applying diphenylammonium triflate (DPAT) as catalyst makes this protocol cost-effective, low corrosive and easy to handle. Graphic abstract: [Figure not available: see fulltext.].
- Zhao, Ting-Ting,Song, Jiang-Long,Hong, Feng-Qing,Xia, Jian-Sheng,Li, Jian-Jun
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p. 2857 - 2868
(2019/08/21)
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- PROCESS AND INTERMEDIATES FOR THE PREPARATION OF N-ACYLATED-4-ARYL BETA-AMINO ACID DERIVATIVES
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A process for producing an enantiomerically enriched, pure or enriched and essentially pure compound of Formula I [structure] wherein the R-, or S-configuration at the stereogenic center is marked with an *, which process hydrogenates an enamide compound of formula III [structure] in an organic solvent in the presence of a transition metal precursor complexed to a chiral phosphine ligand catalyst, wherein Ar is phenyl which is unsubstituted or substituted, R1 and R2 are selected from H, Cl - 8 alkyl, C5 - 12 cycloalkyl, aryl and aryl-C 1 - 2-alkyl, or R1 and R2 together with the nitrogen atom to which they are attached form a C4- r member heterocyclic πng system optionally fused with a 5- to 6- member carbocyclic or heterocyclic ring system, and the other substituents are as defined herein.
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Page/Page column 20
(2010/08/04)
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