22 results about "Aldol reaction" patented technology

This invention relates to a chiral preparation method for florfenicol. Specifically, the method uses p-methylsulfonylbenzaldehyde and glycine ester as starting materials, and synthesizes the key chiral intermediate I through an asymmetric aldol reaction process under the action of a pyridinium salt carbonyl catalyst. Subsequently, through reduction, cyclization, fluorination, and hydrolysis ring-opening reactions, the chiral product florfenicol is obtained. Compared with existing technologies, this invention utilizes the strong catalytic ability of small-molecule pyridinium salt carbonyl catalysts, starting from inexpensive and readily available raw materials, to efficiently control the stereoselectivity of the aldol reaction process, highly selectively constructing the two chiral centers on the florfenicol structure, obtaining the desired chiral configuration, and finally synthesizing florfenicol. The preparation method of this invention is simple, rapid, and efficient.

This invention relates to a chiral preparation method for irushlstat. Specifically, the method uses 2,3-dihydro-1,4-benzodioxyl-6-aldehyde and 2-amino-1-(pyrrolidine-1-yl)ethyl ketone as starting materials, and carries out an asymmetric aldol reaction in the presence of a pyridinium salt carbonyl catalyst. Following reduction and amidation reactions, chiral irushlstat is obtained. Compared with existing technologies, this invention utilizes the strong catalytic ability of small-molecule pyridinium salt carbonyl catalysts, starting from inexpensive and readily available raw materials, to rapidly construct the two key chiral centers of the irushlstat structure with high diastereoselectivity and high enantioselectivity, shortening the synthetic steps of irushlstat. Furthermore, the reaction conditions of this invention are mild and the operation is simple.

This invention relates to a method for preparing chiral drosildopa. Specifically, the method uses compound 1 and glycine ester as starting materials, and an asymmetric aldol reaction occurs under the action of a pyridinium salt carbonyl catalyst, followed by hydrolysis to obtain drosildopa. Compared with the prior art, this invention utilizes the strong catalytic ability of small molecule pyridinium salt carbonyl catalysts, starts with inexpensive and readily available raw materials, reduces the steps of introducing and removing protecting groups, shortens the synthetic route, and efficiently synthesizes optically pure drosildopa. Furthermore, the preparation method of this invention is simple to operate and environmentally friendly.

The invention provides a surface imprinting organic catalyst for directionally constructing catalysis and selecting sites, and a preparation method and application of the surface imprinting organic catalyst. According to the method, an aldehyde-alcohol reaction, which is one of important reactions of carbon-carbon bonding, is selected as a target reaction, and a selective cavity matched with a catalytic activity center is constructed on the surface of a magnetic carrier Fe3O4 by adopting a surface molecular imprinting technology and designing template molecules by taking a covalent connection product of a catalyst tryptophan and a target catalytic product as a template. The construction of the surface molecular imprinting cavity ensures that the active center of the catalyst is in full contact with a substrate molecule, the catalytic efficiency is improved, and meanwhile, the imprinting cavity has a certain selective recognition capability, can be matched with a reaction substrate similar to a template structure and a functional group, has a selective catalysis capability in a complex reaction system, and can be used for preparing a catalyst. Wide application prospects are realized.

The present invention relates to a method for preparing α-branched β′-hydroxy carbonyl compounds through enzymatic-catalyzed reductive aldol reaction by reacting α,β-unsaturated carbonyl donors with carbonyl acceptors in the presence of a polypeptide capable of catalyzing reductive aldol reactions and a cofactor, wherein the polypeptide is an enoyl-CoA carboxylase / reductase (Ecr). The replacement of the native CO2 electrophile in enoyl-CoA carboxylases / reductases (Ecrs) by different carbonyl acceptors advantageously creates a new-to-nature biocatalytic route towards α-branched β′-hydroxy carbonyl compounds.

The invention relates to a water-promoted aldol condensation reaction, which is characterized in that aldehydes with different substituent groups and benzofuranone with different substituents are subjected to aldol reaction at a good yield under the condition of taking water as a solvent and dropwise adding toluene under the reflux condition. The reaction has the advantages of environmental friendliness, simple route, simple and easily available raw materials, lower preparation cost, high product yield, simplicity and convenience in operation and the like.

A photoautocatalytic heterogeneous catalyst for asymmetric aldol reaction and a preparation method thereof, the preparation method comprising the following steps: providing a carrier composed of graphene oxide and protonated phosphorus modified graphitic carbon nitride composite; and performing a photo-catalytic thiol-ene click chemistry reaction on the carrier and a thiol-substituted chiral amino acid to obtain the photoautocatalytic heterogeneous catalyst.

The invention belongs to the field of new material development, and particularly relates to a porous aromatic framework material containing proline chiral catalytic sites as well as a preparation method and catalytic application of the porous aromatic framework material. Firstly, a porous aromatic framework material PAF-NBU2-OH containing hydroxyl is synthesized through Suzuki coupling, then a chiral proline structure is introduced to a PAFs framework through a post-modification method, and the porous aromatic framework material PAF-NBU2-OPro containing proline chiral catalytic sites is obtained. Data such as nitrogen adsorption-desorption characterization, thermogravimetric analysis characterization and the like prove that the synthesized material has remarkable porosity and good stability. The PAF-NBU2-OPro obtained by the method shows extremely high activity, excellent enantioselectivity and diastereoselectivity in catalysis of an asymmetric Aldol reaction of p-nitrobenzaldehyde and cyclohexanone, and the catalytic performance of the PAF-NBU2-OPro can still be kept without loss after 30 times of catalytic circulation. The application of the porous aromatic framework material in the field of asymmetric catalysis is greatly expanded.

The invention discloses a method for synchronously synthesizing D-psicose from escherichia coli by using a D-glucose / glycerol composite carbon source system, belongs to the technical field of synthetic biology, and solves the problem of low yield during production of D-psicose. The method comprises the following steps: overexpressing a pgi gene and a glk gene on Escherichia coli, combining an alse gene and an a6pp gene, partially knocking out a pfkA gene, overexpressing an Mlc gene and a glpkG913S gene, and constructing recombinant Escherichia coli capable of growing by using glycerol; then an aldO gene is introduced, and a metabolic pathway for synthesizing D-psicose by taking glycerol as a substrate is constructed by utilizing an rhaD gene and a yqaB gene, so that synchronous synthesis of D-psicose by using a D-glucose / glycerol composite carbon source system is realized. The invention firstly provides a D-psicose synthesis strategy based on integration of aldol reaction and glycolysis pathway, realizes co-utilization of glycerol and D-glucose, and provides a new strategy for industrial production.

A method for preparing neopentyl glycol, the method including: feeding a feed stream containing formaldehyde and isobutyraldehyde to an aldol reactor and subjecting the feed stream to an aldol condensation reaction in the presence of a catalyst to obtain a first reaction product containing hydroxypivaldehyde; feeding the first reaction product to an aldol purification column; feeding the aldol purification column upper discharge stream to a decanter and separating an organic phase stream containing unreacted isobutyraldehyde and the catalyst and an aqueous phase stream containing a catalyst salt; feeding the aqueous phase stream to a saponification reactor to reduce the catalyst salt to a catalyst and recover the catalyst; and feeding the aldol purification column lower discharge stream to a hydrogenation reactor and subjecting the aldol purification column lower discharge stream to a hydrogenation reaction to obtain neopentyl glycol.

The invention discloses an aurone compound and a preparation method thereof. The method adopts a one-pot reaction, is a green aurone synthesis method taking water as a solvent, benzaldehyde with different substituent groups and substituted benzofuranone are taken as raw materials, toluene is dropwise added into the water solvent, aldol reaction is realized under a reflux condition, and a target product is obtained at a good yield. According to the method, water is used as an environment-friendly solvent, reactants are promoted to form a stable transition-state compound through hydrogen-bond interaction, and the stereoselectivity of the reaction is remarkably improved. The reaction conditions are mild, the use of highly toxic reagents, dangerous strong acids, strong alkalis and highly flammable reagents is avoided, and the method has higher environmental protection property and safety. In addition, protection group operation is not needed in the reaction process, the steps are simplified, and the atom economy is improved.

The application discloses a method for preparing pyrrole and furan compounds from marine waste biomass chitin monomer N-acetyl glucosamine. In the method, N-acetyl glucosamine is catalyzed by a composite valence molybdenum catalyst to perform reverse aldol reaction in a salt-containing water system, and then reacts with a beta-bisketone compound, so that the pyrrole and furan compounds are obtained. The introduction of inorganic salt can promote the dehydration process and improve the distribution ratio of the pyrrole compound in the organic phase, so that the pyrrole compound is prepared from N-acetyl glucosamine at a high yield. The application opens up a new way for efficiently preparing pyrrole and furan compounds from marine waste biomass renewable resources under mild conditions.

The invention discloses a low-free-phenol modified furan resin for casting and a preparation method thereof. The cellulose aldehyde compound is prepared by catalytic decomposition of the cellulose compound with the sulfuric acid and the aluminum-containing compound and then replaces part of formaldehyde and acetone for aldehyde-ketone reaction, free aldehyde in the resin is reduced, anacardol replaces part of phenol for reaction, and free phenol in the resin is effectively reduced; the polyhydric alcohol replaces part of furfuryl alcohol to react, and the prepared phenolic aldehyde modified furan resin introduces a straight chain structure on the basis of reducing the furfuryl alcohol content, so that the flexibility of the resin is improved; lignin is modified by six-membered ring lactone to increase reaction active sites and then reacts with furfuryl alcohol, the lignin modified furfuryl alcohol is prepared, the content of free aldehyde of furan resin is reduced, the curing speed of the resin is increased, raw materials do not contain nitrogen, the prepared resin generates less irritant gas in the casting process, and the nitrogen hole defect is avoided.

The invention relates to a photo-autocatalysis heterogeneous catalyst for asymmetric aldol reaction and a preparation method thereof. The preparation method comprises the following steps: providing a carrier formed by compounding graphene oxide and protonated phosphorus modified graphite-like carbon nitride; and carrying out photocatalytic sulfydryl-alkene click chemical reaction on the carrier and sulfydryl-substituted chiral amino acid to obtain the photo-autocatalysis heterogeneous catalyst.

The application belongs to the technical field of raw materials and intermediate preparation in organic synthesis, and relates to a method for preparing a key intermediate of a natural product Brasilicardin A analogue, and the Brasilicardin A is a new immunosuppressive agent, the mechanism of action of which is to inhibit the amino acid transport system L, has strong immunosuppressive activity (IC50=0.057 mu g / ml), and has potential clinical application value. The application belongs to the technical field of raw materials and intermediate preparation in organic synthesis. The preparation method of the key intermediate comprises: Grignard reaction, methylation reaction, iodinated lactone reaction, intramolecular Aldol reaction and the like for preparing a precursor compound of a C ring, and then through diastereoselective alkylation reaction and intramolecular Michael addition reaction, the synthesis of the key intermediate of the Brasilicardin A analogue is completed. The method has the advantages of simplicity and high efficiency, controllable method, high product purity and easy industrial production and the like.

The invention discloses a preparation method of a fluralan N-1 intermediate, which comprises the following steps: S1, carrying out aldol reaction on 4-acetyl-2-methyl benzoic acid and 3 ', 5'-dichloro-2, 2, 2-trifluoroacetophenone under the action of alkali to obtain an intermediate 1; s2, dehydrating the intermediate 1, washing a mixed product obtained by reaction with diluted hydrochloric acid under a heating condition in a post-treatment process, and directly carrying out next-step reaction on a collected organic phase; and S3, adding the organic phase obtained in the step S2 into a mixed catalytic system of tetrabutylammonium bromide and 18-crown ether-6, and carrying out an intramolecular nucleophilic addition reaction to obtain the fluralan N-1 intermediate. According to the method, a second process route of the fluralana N-1 intermediate is optimized, the yield is increased, the cost is reduced, the process steps are reduced, and the method is a process route which is environmentally friendly, safe, economical, low in production cost and capable of achieving industrial production and has a very good prospect.

This invention relates to a chiral method for preparing thiamphenicol. Specifically, the method uses p-methylsulfonylbenzaldehyde and glycine ester as starting materials, and carries out an asymmetric aldol reaction in the presence of a pyridinium salt carbonyl catalyst, followed by a reduction and amidation reaction to obtain thiamphenicol. This invention utilizes the strong catalytic ability of small-molecule pyridinium salt carbonyl catalysts, starts with inexpensive and readily available raw materials, reduces the steps of introducing and removing protecting groups, shortens the synthetic route, and efficiently synthesizes optically pure thiamphenicol. Furthermore, the preparation method of this invention is simple to operate and environmentally friendly.

The application relates to a method for synchronously synthesizing D-allulose by using a D-glucose / glycerol composite carbon source system, and belongs to the field of synthetic biology, and solves the problem of low yield in the production of D-allulose. The method is characterized in that the pgi gene and the glk gene are overexpressed on Escherichia coli, the alse gene and the a6pp gene are combined, the pfkA gene is partially knocked out, the Mlc gene and the glpk G913S gene are overexpressed, and the recombinant Escherichia coli capable of growing by using glycerol is constructed; the aldO gene is introduced, the metabolic pathway for synthesizing D-allulose by using glycerol as a substrate is constructed by using the rhaD gene and the yqaB gene, and then the D-glucose / glycerol composite carbon source system is used to synchronously synthesize D-allulose. The application firstly proposes a D-allulose synthesis strategy based on integrated aldol reaction and glycolysis pathway, realizes the co-utilization of glycerol and D-glucose, and provides a new strategy for industrial production.

The present application relates to a kind of spherical chiral covalent organic framework and its preparation method and application, the spherical chiral covalent organic framework of proline fragment-containing spherical chiral L DTP-TAPB COF material, the L DTP-TAPB COF material has higher crystallinity, spherical morphology, and contains abundant tetrahydropyrrole chiral catalytic sites, can be applied in asymmetric aldol reaction and shows excellent catalytic activity. In the reaction of catalyzing p-nitrobenzaldehyde and cyclohexanone, the reaction yield is as high as 96%, and the ee value can reach 87%, higher than the catalytic performance of most reported chiral COFs and chiral metal organic framework catalysts. At the same time, it also presents excellent recycling property.

The present invention relates to the technical field of catalytic organic synthesis, and in particular to a calix[4]arene cyclohexanediamine derivative and a method for green catalytic asymmetric Aldol reaction thereof. Aromatic aldehyde and cyclic ketone are used as raw materials, a calix[4]arene cyclohexanediamine derivative is used as a phase transfer catalyst, p-nitrobenzoic acid is used as an additive, and water is used as a solvent. The reaction is carried out at 25°C for 24 to 48 hours. After the reaction is completed, dichloromethane is added, and the organic phase is extracted and separated. The organic phase is dried with anhydrous Na2SO4, and purified by column chromatography to obtain an Aldol product. The synthesis process conditions of the calix[4]arene cyclohexanediamine derivative of the present invention are mild, the catalytic reaction efficiency is high, the asymmetric Aldol reaction catalyzed by the derivative uses water as a solvent, is green and environmentally friendly, and the catalytic reaction can obtain good dr value and ee value under room temperature conditions, thus having broad application prospects.

This invention relates to a chiral preparation method for chloramphenicol. Specifically, the method uses p-nitrobenzaldehyde and glycine ester as starting materials, and an asymmetric aldol reaction occurs under the action of a pyridinium salt carbonyl catalyst. Following reduction and amidation reactions, chloramphenicol is obtained. Compared with existing technologies, this invention utilizes the strong catalytic ability of small-molecule pyridinium salt carbonyl catalysts, starting from inexpensive and readily available raw materials, to efficiently control the stereoselectivity of the aldol reaction, and to obtain the desired stereoconfiguration product, chloramphenicol, in a single dose. The preparation method of this invention reduces the protection of active groups, shortens the chiral synthetic route of chloramphenicol, is simple to operate, and is environmentally friendly.

The present invention relates to CoA-independent reductive aldolases derived from ene reductases (ERs) for preparing α-branched β'-hydroxy carbonyl compounds through enzymatic-catalyzed reductive aldol reaction by reacting α,β-unsaturated carbonyl donors with carbonyl acceptors in the presence of a polypeptide capable of catalyzing reductive CoA-independent aldol reactions and a cofactor, wherein the polypeptide is a modified ene reductase (ER). The present invention further relates to a method for preparing α-branched β'-hydroxy carbonyl compounds through enzymatic-catalyzed reductive aldol reaction.