170 results about "Lewis acid catalysis" patented technology

The invention discloses a bio-based super-hydrophobic ultraviolet curing coating which is prepared from the following raw materials in parts by weight: 33-66 parts of plant oil-based active monomers, 20-45 parts of polythiol, 1-40 parts of modified cellulose, 15-150 parts of an organic solvent and 1-5 parts of a photoinitiator, wherein the plant oil-based active monomer is prepared from epoxidized plant oil, unsaturated organic matters and a Lewis acid catalyst, and the unsaturated organic matters contain hydroxyl and carbon-carbon double bonds located at the tail end of a molecular chain. According to the bio-based super-hydrophobic ultraviolet curing coating disclosed by the invention, a three-dimensional interpenetrating network structure is obtained by cross-linking the plant oil-based active monomer, the polythiol and the cellulose in an ultraviolet curing process, a chemical bonding type surface microstructure super-hydrophobic material with excellent wear resistance is constructed, and the preparation method is simple. The invention further discloses application of the bio-based super-hydrophobic ultraviolet curing coating in surface treatment of a base material.

The invention belongs to the field of organic synthetic chemistry, and relates to a preparation method of melatonin and meerythrine indole derivatives and compounds. Specifically, the indole derivative is efficiently synthesized by taking arylamine and carboxylic acid as raw materials through a one-pot two-step reaction in the presence of catalysis of ferric chloride hexahydrate (FeCl3. 6H2O), a ligand, a diazotization reagent, an additive and a solvent under the conditions of visible light irradiation, inert atmosphere and room temperature. According to the method, visible light induced iron-based LMCT catalysis and iron lewis acid catalysis functions are integrated, and efficient integration of diazotization, decarboxylation, free radical coupling and cyclization reaction is achieved. The method has the advantages that raw materials are cheap and easy to obtain, reaction conditions are mild, substrate applicability is wide, functional group compatibility is good, operation is easy, convenient and safe, and environment friendliness is achieved, gram-level scale preparation can be achieved, and a green and efficient synthesis path is provided for indole compounds with biological activity such as melatonin and meerythrine.

The synthesis process comprises the following steps: (1) introducing inert gas into a reactor, adding a solvent, a Lewis acid catalyst and diphenyl ether, then dropwise adding an acyl chloride monomer solution, and synthesizing an intermediate M with a short-chain small molecular structure; (2) continuously dropwise adding an acyl chloride monomer solution into the reactor for reaction, and then adding an end-capping reagent for reaction; and (3) quenching, washing and drying the reaction product in the step (2) to obtain the product. Under the condition that only the Lewis acid is used as the catalyst, the one-pot method is adopted for synthesizing PEKK in two steps, side reactions can be reduced, meanwhile, the dosage of the catalyst is reduced, the production cost is reduced, the post-treatment process is simplified, and the obtained polyether ketone ketone is high in molecular weight and good in heat resistance and mechanical performance.

The invention relates to the technical field of sodium ion battery negative electrode materials, in particular to a method for preparing hard carbon from medium-temperature coal tar-based pitch, which comprises the following steps: (S1) hydrogenating the medium-temperature coal tar-based pitch and a hydrogen donor solvent at high temperature and high pressure to obtain hydrogenated pitch; (S2) mixing the hydrogenated asphalt with a Lewis acid catalyst, and oxidizing in an oxygen-containing atmosphere to obtain first oxidized asphalt; (S3) uniformly mixing the first oxidized asphalt and a modifier, and carrying out secondary oxidation crosslinking to obtain second oxidized asphalt; and (S4) uniformly mixing the second oxidized asphalt and a pore-forming agent, and carrying out heat treatment in an inert atmosphere to obtain the product hard carbon material. The hard carbon material prepared by the method disclosed by the invention is benefited from a specific preparation process, shows relatively high specific capacity and first coulombic efficiency, and also has excellent rate capability. The preparation method is simple, low in cost and easy for large-scale production, and lays a foundation for large-scale production of the sodium-ion battery negative electrode material.

A composition and method can be used in the preparation of various siloxanes. The composition and method employ a fluorinated triarylborane Lewis acid, a hydrocarbonoxy-functional organosilicon compound, and a silyl hydride. The fluorinated triarylborane Lewis acid catalyzes reaction of a hydrocarbonoxy moiety (from the organosilicon compound) and a silicon-bonded hydrogen atom (from the silyl hydride) to form a siloxane bond.

The invention discloses a preparation method of a hydroxyl-functionalized quaternary phosphonium salt polyion liquid super-crosslinked heterogeneous catalyst and an application of the catalyst in catalysis of a cycloaddition reaction of CO2 and epoxide. Trimethoxytriphenylphosphine and dibromo-p-xylene are firstly subjected to quaternary phosphating to form triphenylphosphine-based ionic liquid, and then the triphenylphosphine-based ionic liquid and biphenyl benzyl dichloride can be subjected to aromatic electrophilic substitution reaction in the presence of 1, 2-dichloroethane serving as a solvent and anhydrous aluminum chloride serving as a Lewis acid catalyst to realize cross-linking, so that the triphenylphosphine-based ionic liquid can be prepared. And methoxy can be removed to form hydroxyl, so that the hydroxyl-functionalized quaternary phosphonium salt polyion liquid super-crosslinked polymer is prepared in one step. The resulting heterogeneous catalyst effectively converts CO2 to cyclic carbonates under milder conditions (80 DEG C, 1 atm) in the absence of a soluble co-catalyst.

A low-modulus, high-resilience modified alcohol-based silicone sealant, its preparation method, and its application are disclosed, relating to the field of sealant materials technology. The silicone sealant comprises the following components in parts by weight: 100 parts of α,ω-alkoxysilane ethylidene-terminated polydimethylsiloxane, 30-80 parts of plasticizer, 80-150 parts of reinforcing filler, 0.5-20 parts of silane crosslinking agent, 0.5-10 parts of silane tackifier, and 0.01-1 part of Lewis acid catalyst; wherein the plasticizer is α-alkoxysilane ethylidene-terminated polydimethylsiloxane. The low-modulus, high-resilience silicone sealant of this invention exhibits fast surface drying speed, low modulus, high elastic recovery rate, good adhesion, and weather resistance.

The invention discloses a preparation method and application of a high-purity cannabidiol heptyl derivative CBDP, and belongs to the technical field of organic synthesis compounds. In order to solve the technical problems of low purity, complex process and high cost of cannabidiol heptyl derivatives in the prior art, the invention provides a preparation method with high purity and simple preparation process. The key points of the technical scheme are as follows: (1) 5-heptylresorcinol and (1S, 4R)-1-methyl-4-(1-methylvinyl)-2-cyclohexene-1-alcohol are dissolved in a solvent and react under the action of a Lewis acid catalyst, and a cannabidiol heptyl derivative CBDP is obtained; (2) dissolving a cannabidiol heptyl derivative CBDP in a solvent, reacting with a derivatization reagent, and purifying to obtain an intermediate 7; and (3) dissolving the intermediate 7 in a solvent, and purifying through an enzyme hydrolysis reaction to obtain the high-purity cannabidiol heptyl derivative CBDP.

The invention discloses a method for preparing an aromatic phosphate salt nucleating agent by using nanoscale aluminum chloride, and belongs to the technical field of polymer nucleating agents. 2, 2-methylene-bis (4, 6-di-tert-butylphenol) and phosphorus oxychloride are used as raw materials, the nanoscale aluminum chloride with the particle size of 20-50nm is selected as an inorganic Lewis acid catalyst and acid binding agent, and the aromatic phosphate salt nucleating agent is prepared by using a one-step method. The preparation method comprises the following steps: replacing the traditional organic acid-binding agents such as triethylamine and pyridine, and synthesizing bis [2, 2 '-methylene bis (4, 6-di-tert-butylphenoxy) phosphate] hydroxyl sodium salt by a one-pot method of condensation, hydrolysis for salt removal and neutralization for salt formation; the purity of the product can reach 99% or above through one-time suction filtration, multiple times of washing are not needed, salt-containing wastewater can be recycled as industrial water after being neutralized, and the environmental protection pressure is greatly reduced; the nucleating agent is suitable for modification processing of polymers such as polypropylene (PP), polyethylene glycol terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA) and the like, and especially meets the strict requirements on the purity and environmental protection property of the nucleating agent in an olefin polymerization process.

The present disclosure relates to the field of drug synthesis, and discloses a method for the preparation of trans-N-benzyloxycarbonyl-(3-hydroxy-2-piperidinyl)-2-propanone as an intermediate of halofuginone. In the preparation method according to the present disclosure, for the first time, trans-N-benzyloxycarbonyl-(3-hydroxy-2-piperidinyl)-2-propanone as shown in Formula I is obtained from amino-substituted pentanal and a thiazolyl sulfoxide compound as raw materials by Mislow-Evans rearrangement reaction and subsequent Lewis acid catalysis. The method for the preparation of trans-N-benzyloxycarbonyl-(3-hydroxy-2-piperidinyl)-2-propanone as an intermediate of halofuginone according to the present disclosure has high yields and stable qualities, provides a new reference route for the synthesis of trans-N-benzyloxycarbonyl-(3-hydroxy-2-piperidinyl)-2-propanone, avoids the reduction of pyridine, and overcomes the disadvantage of requiring the use of an expensive metal catalyst Rh / Al2O3.

The invention discloses a preparation method of high-purity 2-fluoroethanol, and particularly relates to the technical field of preparation of 2-fluoroethanol, which comprises the following steps: S1, in a dual-catalyst system consisting of a phase transfer catalyst and a Lewis acid catalyst and an organic solvent, carrying out fluoridation reaction on 2-chloroethanol and anhydrous potassium fluoride at 60-120 DEG C for 2-10 hours to obtain 2-chloroethanol; and S2, sequentially carrying out integrated purification of filtration, reduced pressure distillation, adsorption treatment and rectification on the reaction mixture. According to the invention, through synergistic activation and mass transfer of double catalysts, the reaction rate and selectivity are significantly improved, the water segregator is utilized to remove reaction water to push equilibrium movement, the conversion rate is improved, and water and impurities are systematically removed by virtue of composite adsorption and precise rectification of molecular sieves and activated carbon, so that high-quality 2-fluoroethanol with high purity and low moisture is finally obtained. The whole preparation process is mild in condition, high in yield, good in safety and suitable for industrial production.

The embodiment of the invention provides a method for preparing high-performance heavy alkyl benzene sulfonic acid barium salt by modifying a heavy alkyl benzene raw material, and relates to the technical field of synthesis of lubricating oil additives. The method for preparing the high-performance heavy alkyl benzene sulfonic acid barium salt by modifying the heavy alkyl benzene raw material comprises the following steps: S1, selecting narrow-fraction long-straight-chain alpha-olefin with the carbon number range of C10-C14 as an alkylating agent, and carrying out Friedel-Crafts alkylation reaction on the alkylating agent and benzene in the presence of a Lewis acid catalyst at the reaction temperature of 30-70 DEG C according to the molar ratio of the benzene to the alpha-olefin of 3: 1-8: 1; the reaction time is 1-4 hours, and after the reaction is completed, carrying out hydrolysis, layering and distillation purification; by physically mixing the narrow-fraction long-straight-chain alpha-olefin synthesized heavy alkylbenzene with regular structure and low branching degree with commercially available heavy alkylbenzene, the molecular homogeneity of the raw material is optimized, the reaction consistency and the salifying stability are improved on the premise of not changing the existing process, and the barium heavy alkylbenzene sulfonate product with better damp-heat and salt spray performance is prepared.

The invention provides a green preparation method and application of diphenyl phosphine oxide. The preparation method comprises the following steps: step 1, mixing diphenyl alkoxy phosphine, water and Lewis acid, and fully stirring for reaction to obtain a reaction solution containing diphenyl phosphine oxide and alcohol; step 2, distilling the reaction liquid, washing with water, standing, separating liquid, collecting an organic phase, drying the organic phase, and cooling and crystallizing to obtain diphenylphosphine oxide; and step 3, rectifying and purifying the distilled alcohol, and pumping the distilled acid and water washing liquid into a reaction kettle for cyclic catalysis. The diphenylalkoxyphosphine is used as a raw material and is subjected to hydrolysis reaction with water under the catalysis of the lewis acid to generate diphenylphosphine oxide and alcohol, the lewis acid can be continuously returned to the reaction kettle to participate in the reaction after being subjected to subsequent distillation, the synthesis process is simple, the atom economy is high, the reaction principle is simple, the conditions are easy to control, and the method is green and environment-friendly and can be used for industrial production.

The application discloses a kind of dodecacyclo triene functionalized flame-retardant polyphenyl ether oligomer and its synthesis method, application, belong to polymer synthesis technical field, dodecacyclo triene is combined with P-H bond compound and is added by radical initiation to contain phosphorus dodecacyclo diene;Again with 2,6-dimethylphenol is added by Lewis acid catalysis to obtain phosphorus-containing dodecacyclo bisphenol;Subsequently with 2,6-dimethylphenol is catalyzed by copper complex and is oxidized and polymerized, and phosphorus-containing dodecacyclo polyphenyl ether oligomer is generated;After terminal functionalization under the basic condition of vinyl benzyl chloride, copolymerization is carried out with peroxide, and the target flame-retardant polyphenyl ether oligomer is prepared.The application introduces dodecacyclo triene bulky rigid cyclic structure in polyphenyl ether oligomer molecular chain, constructs integrated intrinsic flame-retardant system, and the combustion performance of material can be stabilized to reach V-0 grade, and excellent low dielectric, low loss performance is endowed to material.

This invention relates to an electrolyte for lithium-ion batteries or lithium metal batteries, a method for preparing the electrolyte, and a lithium battery. The electrolyte comprises a lithium salt, an organic solvent, and functional additives, wherein the functional additives include aluminum alkoxide compounds. A battery containing the additives is also provided. Based on the discovery that ethylene carbonate (EC) degrades battery thermal safety under high-temperature thermal abuse conditions, aluminum isopropoxide is innovatively introduced as a functional additive. This additive is stable at room temperature, but under high-temperature thermal abuse scenarios, it can act as a Lewis acid catalyst, specifically catalyzing the ring-opening polymerization reaction of EC in the electrolyte to generate polymer segments. Compared with existing technologies, the electrolyte provided by this invention effectively improves the high-temperature storage performance and thermal shock resistance of the battery without sacrificing its room-temperature electrochemical performance.

The present invention relates to the technical field of organic synthesis, and in particular to a 2-cyanoindole-substituted gem-difluoroolefin compound and its preparation method and application. The compound preparation method comprises: using trifluoromethylindolemethanol compounds and trimethylsilyl cyanide as raw materials, and heating the reaction in a solvent under the action of a Lewis acid catalyst and an inorganic base to obtain the 2-cyanoindole-substituted gem-difluoroolefin compound. The present invention provides a 2-cyanoindole-substituted gem-difluoroolefin compound and its preparation method. The method uses trifluoromethylindolemethanol compounds and trimethylsilyl cyanide, which are easily available, as raw materials, and does not require the use of explosive diazo compounds. It has the advantages of mild reaction conditions, simple operation, high yield, and a wide range of reaction substrates.

The application discloses a method for synthesizing an alpha-position chiral nitrogen heteroaromatic ring under the synergistic catalysis of a chiral phosphoric acid and a Lewis acid, and the method comprises the following steps: taking a nitrogen heteroaromatic ring olefin I as an electrophilic reagent, taking an aryl alkyl boronic acid II as a carbon nucleophile, and under the synergistic catalysis of a Lewis acid catalyst and a chiral phosphoric acid catalyst, in the presence of an organic solvent, an additive and a proton source, performing a conjugate addition-asymmetric protonation reaction to generate an alpha-position chiral nitrogen heteroaromatic compound shown in formula V, and the reaction is shown as follows: The application provides a conjugate addition-asymmetric protonation strategy for a nitrogen heteroaromatic ring olefin, which is synergistically catalyzed by a chiral phosphoric acid and a Lewis acid (Fe(OTs)3) and involves an organic boron reagent, a series of alpha-position chiral nitrogen heteroaromatic compounds are successfully synthesized by using the catalytic system, the highest enantioselectivity reaches 98% ee, and good universality is shown for aryl, heterocyclic and polysubstituted substrates, and the bottleneck problem of low reactivity of 1,1-disubstituted substrates in a traditional method is effectively overcome.

Disclosed is a method for synthesizing a silica reinforced polyester adhesive. The method comprises: dissolving an organic acid and a polyol under a first predetermined set of conditions to obtain an adduct; adding silica to the adduct to obtain a silica-adduct mixture under the first predetermined set of conditions; and adding a Lewis acid catalyst to the silica- adduct mixture under a second predetermined set of conditions to obtain the silica reinforced polyester adhesive. Disclosed also is a method for obtaining a silica from a silica-rich lignocellulosic biomass.

The application provides a high-toughness methyl silicone resin and a preparation method thereof. The high-toughness methyl silicone resin comprises the following raw materials in parts by mass: 100 parts of methyltrimethoxysilane; 18-24 parts of dimethyldimethoxysilane; 10-12 parts of a polyhydroxy steric-modified agent; 20-26 parts of water; 36-44 parts of an organic solvent; 0.1-0.3 parts of a titanate catalyst; and 0.1-0.3 parts of an organic tin catalyst. The polyhydroxy steric-modified agent is a topological structure compound containing at least two active hydroxyl groups, which is prepared by an addition reaction of a multifunctional aliphatic polyol and an unsaturated bridged cyclic alicyclic compound under the catalysis of a Lewis acid, and the active hydroxyl group content of the topological structure compound is 3.5-4 mmol / g. The high-toughness methyl silicone resin is applied in the preparation of a flexible sealing material or a heat-resistant coating material for a heating pipe.

This invention discloses a heat-insulating, high-temperature-resistant polyurethane rigid foam material and its low-temperature preparation method, which relates to the field of polyurethane foam materials. Bismaleimide powder is liquefied and dispersed in a polyol through a DA reaction. Lewis acid catalysis shortens the reaction time and is reused as a foaming catalyst. Combined with the excellent high- and low-temperature performance of the polyol, a thermoreversible DA adduct is introduced to achieve endothermic temperature control during the foaming process and low-temperature reconstruction of a rigid cross-linked structure. A low-boiling point primary foaming agent is compounded with methyl formate to reduce the heat of vaporization and system viscosity, and the A / B material preparation temperature is controlled to ≤15°C to avoid foaming agent loss. This solution solves the problems of powder dispersion, viscosity control, and foaming stability at low temperatures, imparting excellent heat-insulating and high-temperature-resistant foam properties.

This invention discloses a biphasic combined Lewis acid hydrolysis method for extracting diosgenin from fenugreek, belonging to the field of natural product extraction technology. The extraction method disclosed in this invention includes: defatting fenugreek raw material, mixing it with a biphasic reaction system composed of Lewis acid, concentrated hydrochloric acid, methanol, water, and petroleum ether, and carrying out a hydrolysis reaction under heating conditions. After the reaction, the organic phase is separated, concentrated, and dried to obtain diosgenin. This invention innovatively introduces a Lewis acid catalyst into the biphasic acid hydrolysis system of fenugreek, achieving significant results such as a 25% reduction in reaction time, a 50% reduction in concentrated hydrochloric acid usage, and a 25% reduction in water usage while ensuring the extraction rate of diosgenin. This method has advantages such as mild conditions, low acid consumption, short processing time, and environmental friendliness, and is suitable for the large-scale green production of diosgenin.

The invention discloses a tall oil acid production method based on synergy of chemical conversion and physical separation, and belongs to the technical field of oleochemical industry. The method creatively utilizes Diels-Alder reaction characteristics of abietic acid and maleic anhydride, and is realized by the following steps: firstly, carrying out vacuum dehydration and degassing pretreatment on crude tall oil; then adding metered maleic anhydride to perform selective conversion under the catalysis of Lewis acid according to the content requirement of the target product abietic acid; performing molecular distillation separation on the reaction product to obtain light fraction fatty acid and heavy fraction abietic acid maleic anhydride resin; and finally, freezing and squeezing to obtain a tall oil acid product with precisely controllable abietic acid content. The technical limitation of a traditional physical separation method is broken through, the added value of the byproduct resin is increased by 50% or above, energy consumption is reduced by 35%, and the method is particularly suitable for customized production of medicine-grade, food-grade and other high-added-value products.

Embodiments described herein generally relate to new processes and processing plants for producing PIB, such as HR-PIB. In an embodiment, a process for producing HR- PIB is provided. The process includes introducing isobutylene into a polymerization reactor, and introducing a polymerization catalyst with the isobutylene to form a mixture comprising the isobutylene and the polymerization catalyst, the polymerization catalyst comprising a Lewis acid catalyst. The process further includes reacting the mixture to form a reaction product mixture comprising an HR-PIB, and introducing a solid substrate with the reaction product mixture, the solid substrate capable of sorbing an amount of polymerization catalyst. The process further includes removing the solid substrate comprising sorbed polymerization catalyst from the reaction product mixture by solid-liquid separation.

The application belongs to the technical field of organic synthesis, and particularly relates to a preparation method of 4-amino-2-methylbenzoic acid, and more particularly relates to a preparation method of 4-amino-2-methylbenzoic acid as a raw material of a tolvaptan intermediate, wherein 3-methylaniline is used as a raw material to prepare 3-methylacetanilide with an acylating agent, the 3-methylacetanilide is subjected to Friedel-Crafts acylation with oxalyl chloride under a Lewis acid catalytic system to prepare 4-acetylamino-2-methylbenzoic acid, and finally, the 4-acetylamino-2-methylbenzoic acid is deprotected under alkaline conditions, and then acidified to obtain the target compound 4-amino-2-methylbenzoic acid, wherein the raw material used in the preparation method is cheap and easy to obtain, the production equipment has low requirements, the process condition is simple, the safety factor is high, no ammonia nitrogen and other three wastes are generated, the cost is low, and the industrialized production is easy to implement.

The invention discloses a smoke-suppressing low-toxicity flame-retardant floor board and a preparation method thereof. The method comprises the steps that S1, wood is placed in a mixed solution of imidazole diethyl phosphate and a Lewis acid catalyst, vacuum impregnation and heating and pressurizing impregnation are sequentially conducted, and the wood is drained after impregnation; the wood is sequentially placed in a chitosan solution, a metal salt solution and an alkaline solution to be subjected to pressure dipping, and complexing flame retardant modified wood is obtained after draining and washing; and S2, the complex flame retardant modified wood is soaked in a water-soluble charring agent solution, drained after being pressurized and soaked, washed with water and dried, and the flame retardant modified wood is obtained. The imidazole diethyl phosphate is obtained by carrying out condensation reaction on 1-(3-aminopropyl) imidazole and (formyl methyl) diethyl phosphate in a mass ratio of (0.5-0.7): 1. The problems that a current floor board is poor in flame retardant property durability, high in smoke density and low in carbon residue amount can be effectively solved.

This invention relates to the field of organic compound preparation technology, specifically a method for preparing 11-triglycerides of carbonate via low-temperature acylation. This method uses glycerol and undecanoyl chloride as raw materials, employing a synergistic system of a "composite acid-binding agent + Lewis acid catalyst," and combines in-situ dehydration technology and a stepwise heating strategy in a dual-solvent environment to achieve efficient synthesis. The specific steps include: under nitrogen protection, dissolving glycerol in a dichloromethane-toluene dual solvent, adding a composite acid-binding agent of pyridine and N,N-diisopropylethylamine, anhydrous zinc chloride catalyst, and 4A molecular sieve for in-situ dehydration; dropwise adding undecanoyl chloride at a low temperature of 5-10°C, followed by sequential heating to 30°C for 2-3 hours and then reacting at 50°C for 12-16 hours; and post-processing using a combined process of filtration-multi-stage extraction-membrane separation-column chromatography. This invention provides mild reaction conditions, effectively suppresses side reactions, produces high-purity products, increases molar yield, and reduces solvent toxicity and purification costs.

The invention provides a method for preparing HFO-1243zf by coupling VDF and R152a, which is characterized in that a target product is synthesized in one step under the conditions of 50-80 DEG C and 0.5-1.5 MPa through lewis acid catalytic addition reaction. Comprising the steps of raw material purification (VDF is greater than or equal to 99.5%, and R152a is greater than or equal to 99.0%), catalytic addition (a catalyst is an AlCl / FeCl / ZnCl homogeneous phase or load type), and product refining (water washing, alkali washing and vacuum rectification). The method breaks through the limitation of a traditional multi-step process, the VDF conversion rate is larger than or equal to 80%, the HFO-1243zf selectivity is larger than or equal to 90%, the purity is larger than or equal to 99.5%, the reaction energy consumption is reduced by 55%, and the equipment cost is reduced by 50%. The method is simple in process, mild in condition and low in cost, an efficient and environment-friendly technical scheme is provided for industrial production of HFO-1243zf, and the method has important significance in promoting development of a low-GWP refrigerant industry chain.

A composition includes a silyl hydride (having at least one silicon-bonded hydrogen atom per molecule) and a fluorinated triarylborane Lewis acid. In the method, the Lewis acid catalyzes reaction of silicon bonded hydrogen atoms from the silyl hydride and water, thereby forming a siloxane bond in the resulting product. The composition and method can be used to form siloxane intermediates and cured networks.

The invention provides high-toughness methyl silicone resin and a preparation method thereof. The high-toughness methyl silicone resin comprises the following raw materials in parts by mass: 100 parts of methyltrimethoxysilane; 18 to 24 parts of dimethyl dimethoxy silane; 10 to 12 parts of a polyhydroxy steric hindrance modifier; 20 to 26 parts of water; 36-44 parts of an organic solvent; 0.1 to 0.3 part of a titanate catalyst; 0.1 to 0.3 part of an organic tin catalyst; the polyhydroxy steric hindrance modifier is a topological structure compound containing at least two active hydroxyl groups and prepared by an addition reaction of polyfunctional aliphatic polyol and an unsaturated bridged ring alicyclic compound under the catalysis of Lewis acid, and the content of the active hydroxyl groups is 3.5-4mmol / g. The high-toughness methyl silicone resin is applied to preparation of a flexible sealing material or a heat-resistant coating material for a heating pipeline.

The invention discloses a synthesis method of 9-bromoanthracene, and belongs to the technical field of organic synthesis. According to the method, anthracene is used as a raw material, inorganic bromine salt is used as a bromine source, hydrogen peroxide is used as an oxidizing agent, and 9-bromoanthracene is synthesized in a mixed solvent in a high-selectivity manner under the catalysis of composite Lewis acid; and purifying the crude product through stepped step-by-step recrystallization to obtain a high-purity product. Through the synergistic effect of the composite catalytic system and the mixed solvent, generation of a 9, 10-dibromoanthracene byproduct difficult to remove is inhibited from the source, and efficient separation of the product and key impurities can be realized without column chromatography in combination with a gradient cooling fractional crystallization process. The method is green and safe in process, simple to operate, low in cost and easy to industrialize, and the prepared 9-bromoanthracene can meet the application requirements of OLED photoelectric materials and other high-end fields.