14 results about "Quaternary carbon" patented technology

This application discloses a method for synthesizing chiral cyano-containing full-carbon quaternary cyclic compounds, characterized by the following steps: mixing a solvent, an oxidant, an alkynyl malononitrile compound, a carboxylic acid compound, a palladium salt, and a chiral dinitrogen ligand; reacting the mixture; drying; and separating to obtain the chiral cyano-containing full-carbon quaternary cyclic compound. This method can achieve a palladium-catalyzed tandem reaction of alkynyl malononitrile with a carboxylic acid involving asymmetric acyl oxidative cyclization / acyl migration, yielding cyano-containing full-carbon quaternary cyclic compounds with optical purity in good yields (enantiomer ratios up to 96.5:3.5). This invention features a broad substrate range, readily available raw materials, simple and practical operation, and mild reaction conditions.

This invention belongs to the fields of organic catalysis and asymmetric catalysis, and relates to a bichiral synergistic nitrogen heterocyclic carbene-oxynitrile adduct catalyst, its preparation method, and its application. The catalyst is composed of a nitrogen heterocyclic carbene unit and an oxynitrile unit, wherein both the nitrogen heterocyclic carbene and oxynitrile moieties can incorporate chiral structural units, thereby constructing a synergistic chiral environment composed of two chiral sources within the overall catalyst structure. This structural design allows for a more refined stereoselectivity control during the catalytic reaction, thereby enhancing the catalyst's stereoinductive ability in asymmetric catalytic reactions. The catalyst is prepared through a modular synthesis process, which involves fewer steps and is safe and simple to operate, and the catalyst structure is easily modulated. Applying this catalyst to acyl rearrangement reactions enables effective control of the reaction's stereoselectivity, thereby efficiently synthesizing various indolones or benzofuranones containing a chiral quaternary carbon center at the C3 position.

This invention discloses a dispironaphthyl-1,3'-indene-1',2"-pyrrolidone derivative, its synthetic method, and its applications, relating to the field of organic synthesis technology. Its structural formula is shown in Formula I. The series of dispironaphthyl-1,3'-indene-1',2"-pyrrolidone derivatives provided by this invention contain two quaternary carbon centers, exhibiting a novel structure. The naphthalene ring skeleton is connected to an indene ring, which in turn is connected to a pyrrolidone skeleton. The preparation method provided by this invention uses a simple starting compound, readily available raw materials, mild reaction conditions, simple operation, short preparation cycle, and high yield. It exhibits significant inhibitory effects on tumor cells and can be used to prepare antitumor drugs, laying the foundation for the synthesis and application of such chiral drug skeletons and providing new ideas.

This invention provides a method for synthesizing milobalin benzylsulfonic acid, comprising the following steps: a chiral enone undergoes a condensation reaction with cyanoacetate in the presence of ammonium acetate to obtain an unsaturated cyano ester; next, the unsaturated cyano ester undergoes a condensation reaction with nitromethane to obtain a nitro ester; the nitro ester is then deesterified at high temperature to obtain a chiral nitro nitrile, which is then reduced to a chiral amino nitrile; subsequently, the chiral amino nitrile is hydrolyzed to obtain the free base of milobalin; finally, the free base of milobalin is salted with benzylsulfonic acid to obtain milobalin benzylsulfonic acid. This invention stereospecifically constructs a chiral cyclobutane quaternary carbon center to obtain a chiral nitro ester with a single stereoconfiguration, avoiding the chiral isomer waste generated by chiral isomer resolution, eliminating the need for chiral column separation or chiral resolution, significantly reducing production costs, and simultaneously avoiding the environmental pollution caused by residual heavy metal titanium in the product and solid waste heavy metal titanium.

This invention belongs to the field of polyaryletherketone resin preparation technology, and relates to a method for preparing polyaryletherketone with low crystallinity and low melting point. Under nitrogen protection, 4,4'-difluorobenzophenone, anhydrous sodium carbonate, hydroquinone, biphenyl, and bisphenol A are added to a solvent, stirred and mixed evenly, and then heated for polymerization to obtain polyaryletherketone with low crystallinity and low melting point. The molar ratio of hydroquinone, biphenyl, and bisphenol A is 55~75:5~25:5~20. This invention uses a precise compounding system of three phenol monomers, hydroquinone, biphenyl, and bisphenol A, to achieve fine control of the molecular chain structure. By disrupting the regularity of the molecular chain through the quaternary carbon atoms in bisphenol A, the crystallinity and melting point are reduced. Biphenyl compensates for the loss of rigidity, while hydroquinone retains its intrinsic properties. This solves the problem of "reduced melting point inevitably leads to reduced heat resistance / mechanical properties" in existing technologies from the root of molecular structure.

The application discloses a synthesis method of alpha-substituted arylacetamide compounds. The method is based on a light-driven iron-catalyzed decarboxylative arylalkylation reaction system of ligand-metal charge transfer (LMCT) mechanism, can efficiently couple readily available N-arylacrylamide with commercial and various carboxylic acids, and can prepare a series of alpha-substituted arylacetamide compounds containing acyclic quaternary carbon stereogenic centers with high chemical selectivity. The system is suitable for various carboxylic acid substrates, including primary, secondary and tertiary alkyl carboxylic acids and complex biological active carboxylic acid molecules.

The application provides methods of β- and γ-C(sp3)-H heteroarylation of diverse quaternary carbon centers of free aliphatic carboxylic acids using bidentate pyridine-pyridone ligands. Herein disclosed are methods of Pd(II)-catalyzed mono-selective β- and γ-C(sp3)-H aza-heteroarylation of free carboxylic acids, including a-hydrogen containing substrates, with high yields and high mono-selectivity.

The composition comprises: a quantum dot material and a first additive, wherein the first additive is selected from any one of the following structures represented by general formula (I): where R1 is selected from any one of an amino group, an alkyl-substituted amino group, a hydroxyl group, an alkoxy group, and an alkyl group; R2 is selected from any one of a substituted or unsubstituted alkylene group, a substituted or unsubstituted oxyalkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted heterocycloalkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, and a substituted or unsubstituted fused arylene group; R3 is selected from any one of secondary carbon, tertiary carbon, and quaternary carbon; n1 is a positive integer greater than or equal to 2; and under preset conditions, the first additive and the quantum dot material are bonded by means of chemical bonds.

The application discloses a method for preparing a full-carbon quaternary carbon center derivative through radical-initiated olefin and alkyne cross-coupling, which overcomes the problem that a tertiary carbon radical generated in situ has a large steric hindrance and is difficult to react with a cross-coupling reagent to construct a full-carbon quaternary carbon center by using the guiding effect of a guiding group. The method uses 1,1-disubstituted electron-deficient olefin, O-(tert-butyloxycarbonyl) cyclobutanone oxime compound and terminal alkyne as raw materials, and reacts at room temperature under the presence of a catalyst, a base and a solvent in an inert atmosphere. After the reaction is completed, N-(pyridine-2-yl)-6-cyano-2-aryl-2-alkynyl hexanamide derivatives are obtained through separation and purification. The method has good substrate adaptability and simple operation advantages.

This invention relates to the field of organic synthesis and discloses a method for the visible-light photocatalytic synthesis of 3-fluoroindole oxides. This method utilizes a benzothiazole-substituted sulfone group as the leaving group, achieving efficient preparation of 3-fluoro-3-alkyl-N-methylindole oxides with a fluorine-containing quaternary carbon center under excited-state photocatalytic redox conditions. Compared with traditional methods for synthesizing 3-fluoroindole oxides, this invention has the following advantages: convenient substrate preparation; mild reaction conditions; and good functional group compatibility.

This invention relates to the field of organic synthesis, specifically to a method for the in-situ reaction of an α-diazoketone with a Wolff rearrangement to generate an enone, sodium pentafluorophenolate, and an allyl halide, yielding a pentafluorophenol ester, a tertiary carboxylic acid containing a quaternary carbon center. In this invention, under a nitrogen atmosphere, α-diazoketone, tetrakis(triphenylphosphine)palladium, sodium pentafluorophenolate, and an allyl halide are sequentially added to a reaction solvent. The mixture is stirred at 25°C under 15W blue LED illumination until the reaction is complete. After filtration and purification, the pentafluorophenol ester product containing a quaternary carbon center is obtained. The preparation method of this invention is simple to operate (the reactive enone participates in the reaction in situ via the Wolff rearrangement), has high atom economy, mild conditions, and good substrate universality.

This invention discloses an asymmetric method for synthesizing fluorine-containing chiral quaternary carbon compounds, relating to the field of organic synthesis techniques. The method includes: using a carboxylic acid compound of Formula 1 and isopropanol as starting materials, and under the action of a catalyst, activating reagent, and base, with a fluorinated reagent as the fluorine source, reacting in an organic solvent to obtain an α-fluoro-α-substituted isopropyl carboxylate as shown in Formula 2. Using a carboxylic acid compound and isopropanol as starting materials, and under the action of a specific catalyst, activating reagent, and base, with a fluorinated reagent as the fluorine source, a specific reaction route is used to achieve highly enantioselective construction of α-fluoro-α-substituted carboxylic acid ester structures. This method has advantages such as mild reaction conditions, simple operation steps, and a wide range of applicable substrates, providing a new and effective approach for enriching the methods for constructing fluorine-containing chiral quaternary carbon compounds.

This invention discloses a method for the asymmetric hydroboration synthesis of methylene cyclobutane derivatives containing chiral quaternary carbons, belonging to the field of organic synthesis technology. This invention utilizes conjugated dimethylene cyclobutane derivatives and borane as reaction substrates, chiral bisphosphine ligands as ligands, and a metal catalyst to synthesize boron-substituted chiral cyclobutane derivatives. Based on the obtained boron-substituted chiral cyclobutane, a chiral cyclobutanol derivative is synthesized by combining a two-step one-pot oxidation process. This invention also provides a novel copper-catalyzed asymmetric hydroboration method for constructing cyclobutane derivatives containing chiral quaternary carbon centers.