CN115634718B - Preparation method and application of graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst - Google Patents
Preparation method and application of graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst Download PDFInfo
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- 239000003054 catalyst Substances 0.000 title claims abstract description 107
- 239000010949 copper Substances 0.000 title claims abstract description 105
- 229920001661 Chitosan Polymers 0.000 title claims abstract description 72
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 59
- 229910052802 copper Inorganic materials 0.000 title claims abstract description 59
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 title claims abstract description 58
- 229910021389 graphene Inorganic materials 0.000 title claims abstract description 54
- 239000004372 Polyvinyl alcohol Substances 0.000 title claims abstract description 44
- 229920002451 polyvinyl alcohol Polymers 0.000 title claims abstract description 44
- 239000004005 microsphere Substances 0.000 title claims abstract description 38
- 239000002131 composite material Substances 0.000 title claims abstract description 36
- 238000002360 preparation method Methods 0.000 title claims abstract description 21
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims abstract description 75
- 238000006243 chemical reaction Methods 0.000 claims abstract description 56
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 47
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims abstract description 33
- 238000000034 method Methods 0.000 claims abstract description 26
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 24
- 239000000654 additive Substances 0.000 claims abstract description 19
- 230000000996 additive effect Effects 0.000 claims abstract description 16
- 238000003756 stirring Methods 0.000 claims abstract description 16
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims description 30
- 238000001035 drying Methods 0.000 claims description 19
- 238000001914 filtration Methods 0.000 claims description 19
- 239000007864 aqueous solution Substances 0.000 claims description 15
- 238000002156 mixing Methods 0.000 claims description 14
- 239000000047 product Substances 0.000 claims description 13
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 12
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical class [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 12
- 150000002148 esters Chemical class 0.000 claims description 12
- 238000005406 washing Methods 0.000 claims description 12
- 239000000243 solution Substances 0.000 claims description 11
- 239000003446 ligand Substances 0.000 claims description 10
- 239000000706 filtrate Substances 0.000 claims description 9
- 239000002253 acid Substances 0.000 claims description 8
- -1 o-methylphenyl Chemical group 0.000 claims description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 7
- 239000012074 organic phase Substances 0.000 claims description 7
- 238000004064 recycling Methods 0.000 claims description 7
- 239000007787 solid Substances 0.000 claims description 7
- 239000000126 substance Substances 0.000 claims description 7
- 238000009210 therapy by ultrasound Methods 0.000 claims description 7
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 6
- 238000004440 column chromatography Methods 0.000 claims description 6
- 239000003208 petroleum Substances 0.000 claims description 6
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 claims description 6
- 239000012286 potassium permanganate Substances 0.000 claims description 6
- BMIBJCFFZPYJHF-UHFFFAOYSA-N 2-methoxy-5-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine Chemical compound COC1=NC=C(C)C=C1B1OC(C)(C)C(C)(C)O1 BMIBJCFFZPYJHF-UHFFFAOYSA-N 0.000 claims description 5
- SXRSQZLOMIGNAQ-UHFFFAOYSA-N Glutaraldehyde Chemical compound O=CCCCC=O SXRSQZLOMIGNAQ-UHFFFAOYSA-N 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 5
- 229910000365 copper sulfate Inorganic materials 0.000 claims description 5
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 claims description 5
- 229910002804 graphite Inorganic materials 0.000 claims description 5
- 239000010439 graphite Substances 0.000 claims description 5
- 125000000094 2-phenylethyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])([H])C([H])([H])* 0.000 claims description 4
- 239000011734 sodium Substances 0.000 claims description 4
- 125000001544 thienyl group Chemical group 0.000 claims description 4
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 3
- 239000012043 crude product Substances 0.000 claims description 3
- 238000004090 dissolution Methods 0.000 claims description 3
- 238000000227 grinding Methods 0.000 claims description 3
- 125000003854 p-chlorophenyl group Chemical group [H]C1=C([H])C(*)=C([H])C([H])=C1Cl 0.000 claims description 3
- 238000002791 soaking Methods 0.000 claims description 3
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 3
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 claims description 2
- 239000005751 Copper oxide Substances 0.000 claims description 2
- 239000012295 chemical reaction liquid Substances 0.000 claims description 2
- 238000004140 cleaning Methods 0.000 claims description 2
- 229910000431 copper oxide Inorganic materials 0.000 claims description 2
- 238000004108 freeze drying Methods 0.000 claims description 2
- 239000003622 immobilized catalyst Substances 0.000 claims 1
- 239000000203 mixture Substances 0.000 claims 1
- 238000012360 testing method Methods 0.000 abstract description 24
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 abstract description 16
- 229910052796 boron Inorganic materials 0.000 abstract description 16
- 230000003197 catalytic effect Effects 0.000 abstract description 14
- 239000000463 material Substances 0.000 abstract description 12
- 230000000694 effects Effects 0.000 description 19
- 230000035484 reaction time Effects 0.000 description 18
- 239000012153 distilled water Substances 0.000 description 17
- 238000007259 addition reaction Methods 0.000 description 13
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 11
- 229910001431 copper ion Inorganic materials 0.000 description 11
- 239000000843 powder Substances 0.000 description 10
- 239000002904 solvent Substances 0.000 description 10
- 238000011068 loading method Methods 0.000 description 9
- 150000001875 compounds Chemical class 0.000 description 8
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 6
- 238000012512 characterization method Methods 0.000 description 6
- 238000001179 sorption measurement Methods 0.000 description 6
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 5
- 239000012071 phase Substances 0.000 description 5
- 238000001228 spectrum Methods 0.000 description 5
- 239000003513 alkali Substances 0.000 description 4
- 239000000543 intermediate Substances 0.000 description 4
- 238000011835 investigation Methods 0.000 description 4
- 230000005588 protonation Effects 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 125000003277 amino group Chemical group 0.000 description 3
- 238000005885 boration reaction Methods 0.000 description 3
- 238000003912 environmental pollution Methods 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
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- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 3
- 230000004580 weight loss Effects 0.000 description 3
- 238000005481 NMR spectroscopy Methods 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000007810 chemical reaction solvent Substances 0.000 description 2
- 230000000536 complexating effect Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 150000002440 hydroxy compounds Chemical class 0.000 description 2
- 238000009776 industrial production Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000012046 mixed solvent Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- MFRIHAYPQRLWNB-UHFFFAOYSA-N sodium tert-butoxide Chemical compound [Na+].CC(C)(C)[O-] MFRIHAYPQRLWNB-UHFFFAOYSA-N 0.000 description 2
- DQFBYFPFKXHELB-UHFFFAOYSA-N Chalcone Natural products C=1C=CC=CC=1C(=O)C=CC1=CC=CC=C1 DQFBYFPFKXHELB-UHFFFAOYSA-N 0.000 description 1
- 229910021591 Copper(I) chloride Inorganic materials 0.000 description 1
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 1
- KFVREYFOFOLMIE-UHFFFAOYSA-N O.O.O.O.[Na+].[Na+].[Na+].[O-]B([O-])[O-] Chemical compound O.O.O.O.[Na+].[Na+].[Na+].[O-]B([O-])[O-] KFVREYFOFOLMIE-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 125000002015 acyclic group Chemical group 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000012300 argon atmosphere Substances 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 238000005271 boronizing Methods 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 235000005513 chalcones Nutrition 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- MXOAEAUPQDYUQM-UHFFFAOYSA-N chlorphenesin Chemical group OCC(O)COC1=CC=C(Cl)C=C1 MXOAEAUPQDYUQM-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 230000021615 conjugation Effects 0.000 description 1
- OXBLHERUFWYNTN-UHFFFAOYSA-M copper(I) chloride Chemical compound [Cu]Cl OXBLHERUFWYNTN-UHFFFAOYSA-M 0.000 description 1
- JZCCFEFSEZPSOG-UHFFFAOYSA-L copper(II) sulfate pentahydrate Chemical compound O.O.O.O.O.[Cu+2].[O-]S([O-])(=O)=O JZCCFEFSEZPSOG-UHFFFAOYSA-L 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 229940045803 cuprous chloride Drugs 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- DPOGTJDEMBEUSH-UHFFFAOYSA-N dicyclohexyl(ethyl)phosphane Chemical compound C1CCCCC1P(CC)C1CCCCC1 DPOGTJDEMBEUSH-UHFFFAOYSA-N 0.000 description 1
- GPAYUJZHTULNBE-UHFFFAOYSA-N diphenylphosphine Chemical compound C=1C=CC=CC=1PC1=CC=CC=C1 GPAYUJZHTULNBE-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002085 enols Chemical class 0.000 description 1
- 238000006345 epimerization reaction Methods 0.000 description 1
- NLFBCYMMUAKCPC-KQQUZDAGSA-N ethyl (e)-3-[3-amino-2-cyano-1-[(e)-3-ethoxy-3-oxoprop-1-enyl]sulfanyl-3-oxoprop-1-enyl]sulfanylprop-2-enoate Chemical compound CCOC(=O)\C=C\SC(=C(C#N)C(N)=O)S\C=C\C(=O)OCC NLFBCYMMUAKCPC-KQQUZDAGSA-N 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- KTWOOEGAPBSYNW-UHFFFAOYSA-N ferrocene Chemical compound [Fe+2].C=1C=C[CH-]C=1.C=1C=C[CH-]C=1 KTWOOEGAPBSYNW-UHFFFAOYSA-N 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
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- 239000007788 liquid Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000002808 molecular sieve Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000010525 oxidative degradation reaction Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
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- 238000011084 recovery Methods 0.000 description 1
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- 238000011069 regeneration method Methods 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 1
- 238000010025 steaming Methods 0.000 description 1
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- DQFBYFPFKXHELB-VAWYXSNFSA-N trans-chalcone Chemical compound C=1C=CC=CC=1C(=O)\C=C\C1=CC=CC=C1 DQFBYFPFKXHELB-VAWYXSNFSA-N 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
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- Catalysts (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a preparation method and application of a graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst, and relates to the field of graphene oxide composite materials. By using the CS-GO-PVA-Cu catalyst, toluene, diethyl ether or methanol is selected as an additive, then water is added for stirring reaction, and an asymmetric boron addition test is carried out, so that the prepared chiral organoboride has the advantages of high product yield, high enantioselectivity, less catalyst consumption, mild reaction conditions and the like; the method is carried out at room temperature, is simple and easy to operate, saves cost and is environment-friendly; and the catalytic material can be reused, thus having potential industrial application value.
Description
Technical Field
The invention relates to the field of graphene oxide composite materials, in particular to a preparation method and application of a graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst.
Background
The organoboride, an important organic compound, can be simply and conveniently converted into other organic compounds. Therefore, how to efficiently construct chiral organoborides is becoming a hotspot for chemists to study. The transition metal catalyzed conjugation of alpha, beta-unsaturated compounds to boronize the beta position of the alpha, beta-unsaturated compound has been studied by many scientists, e.g., catalytic systems constructed of metals such as platinum, rhodium, copper, nickel, etc. all achieve the beta position boronizing of the alpha, beta-unsaturated compound. The copper catalyzed conjugated boronation of alpha, beta-unsaturated compound has been studied widely because of its mild reaction conditions, low cost and easy availability of catalyst, low ligand consumption, good substrate universality, etc.
To date, copper catalyzed α -substitution reactions of α, β -unsaturated substrates still face serious challenges, such as low reactivity of the trisubstituted olefin substrates catalyzed by existing catalytic methods, complex enantioselective control by non-stereospecific protonation, lack of mild neutral conditions to avoid or reduce epimerization and by-product formation. Thus, the success of such reactions is very rare. So far, the work of asymmetrically catalyzing β -boration of α, β unsaturated substrates has focused mainly on the use of copper catalysts under alkaline conditions. In 2014, literature (org.lett.2014, 16, 1426-1429) reports asymmetric conjugated borohydride reactions of beta-substituted alpha-dehydroamino acid derivatives catalyzed by Cu, wherein cuprous chloride is used as a copper source, (S, sp) -ip-foxAP is used as a ligand, sodium tert-butoxide is used as a base, methanol is used as a proton source, a molecular sieve is used as an additive, tetrahydrofuran is used as a solvent, and asymmetric conjugated borohydride reactions of various alpha-dehydroamino acid derivatives are realized at normal temperature. However, the reaction process in the document must be carried out under argon atmosphere, the experimental operation is complex, and the conditions are severe; the dosage of the ligand is huge and the cost is high; a large amount of alkali is needed in the reaction process, so that environmental pollution is easy to cause, and the method is not suitable for industrial production.
Therefore, it is highly desirable to develop a simple, easy, mild, low cost, green and highly productive process for preparing chiral organoborides based on asymmetric borides of α, β -unsaturated esters.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a preparation method and application of a graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst, which solve the problems in the prior art that a large amount of alkali is needed for reaction to cause environmental pollution to a certain extent; the reaction requires an anhydrous and anaerobic environment and a large amount of chiral ligands, has high cost, can not be recycled, and is not suitable for industrial production; the unique compatibility and the space structure of the copper-immobilized catalytic material of the Graphene Oxide (GO)/Chitosan (CS)/polyvinyl alcohol (PVA) composite microsphere are utilized, so that the copper-immobilized catalytic material has larger specific surface area, the complexing capacity for copper is obviously enhanced, and the catalytic activity is higher when the chiral organoboride is prepared; in addition, the chitosan itself contains a large amount of amino groups, so that an alkaline environment is provided for the reaction, the catalytic reaction can be realized in pure water, no alkali is required to be added, and the environment-friendly chemical concept is met; meanwhile, the catalyst is convenient to recycle for a plurality of times, and the method is very suitable for industrial application. Specifically, the method is realized by the following technology.
The invention also provides a preparation method of the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst, which comprises the following steps:
s1, preparing graphene oxide, adding the graphene oxide into a chitosan solution, and performing normal-temperature ultrasonic treatment (the common power is 50-100W, and the frequency is 28-40 kHz) for 15-60min; then adding polyvinyl alcohol and glutaraldehyde, and performing ultrasonic treatment at normal temperature (the parameters are the same as above) for 30-60min to obtain a first system with the mass fraction of graphene oxide of 1-5%; adding absolute ethyl alcohol into a saturated sodium hydroxide aqueous solution, uniformly mixing, and cooling to room temperature to obtain a second system; in general, the volume ratio of the saturated aqueous sodium hydroxide solution to the absolute ethanol may be selected to be 4 (3-8).
S2, dripping the first system prepared in the step S1 into the second system to form microspheres, filtering, cleaning and drying at room temperature;
s3, soaking the product prepared in the step S2 in water at 40-80 ℃ for 1-2 hours, adding excessive copper sulfate aqueous solution, stirring for reaction, filtering to obtain filter residues, drying at 40-60 ℃ for 12-24 hours, and grinding to obtain the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst.
Graphene oxide/chitosan/polyvinyl alcohol prepared by adopting the methodIn the composite microsphere immobilized copper catalyst (CS-GO-PVA-Cu catalyst), chitosan is used for preparing Cu 2+ The adsorption of (a) is mainly based on amino group coordination (formula (2) below), and the main adsorption reaction includes:
protonation of the amino group:
matching:
hydrogen bond adsorption:
electrostatic attraction:
when the pH of the reaction system is low, the reaction system participates in the protonation reaction to form-NH 3+ The number is high, and the catalyst is used for the co-adsorption of Cu 2+ Of (2) NH 2 Less Cu 2+ The complexation with chitosan is reduced.
The chitosan has excellent chelating and adsorbing capacity, can load metal to prepare a catalyst, and has good catalytic effect. Copper is a powerful catalyst, but it is almost insoluble in water and the rest of the organic solvents, so to prepare such catalysts, it is necessary to chemically modify the chitosan before it is loaded with metal. The graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst provided by the invention is prepared by compounding a general CS serving as a matrix material with GO by taking Chitosan (CS) as a matrix and glutaraldehyde as a cross-linking agent, adding a small amount of polyvinyl alcohol (PVA) into the matrix material, carrying out cross-linking modification, and loading copper ions. By adopting the preparation method, the acid resistance of the chitosan is improved, and the complexing effect on copper ions is stronger through chemical adsorption and physical adsorption. The prepared graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst (CS-GO-PVA-Cu catalyst) is subjected to structural morphology, thermal stability and component analysis by a plurality of characterization means such as XRD, SEM, TGA, and the fact that residual copper ions are highest when the mass fraction of GO in a first system is 4% is found, and the prepared copper-loaded catalytic material has the best copper loading effect.
Preferably, in step S1, the preparation method of graphene oxide includes the following steps:
s11, uniformly mixing graphite flakes, concentrated phosphoric acid (83-98% by mass) and concentrated sulfuric acid (98% by mass), and quantitatively adding potassium permanganate in batches; the mass ratio of the graphite flake to the potassium permanganate is 1:5;
s12, stirring the mixed system prepared in the step S11 for 12-24 hours at 40-60 ℃, cooling to room temperature, pouring ice until the ice is dissolved, and adding H into the solution system 2 O 2 The aqueous solution (the mass fraction is generally more than or equal to 20%) is bright yellow, and the solid graphene oxide is obtained after washing and freeze drying.
Preferably, in the step S1, the chitosan solution is prepared by mixing and stirring chitosan with the purity of 100-200mpa.s and acetic acid aqueous solution with the mass fraction of 6-8%, and the concentration of the chitosan is 1-2g/mL.
Preferably, in step S3, the concentration of the copper sulfate aqueous solution is 3-5mol/L.
The invention also provides a method for further preparing the chiral organoboride by utilizing the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst prepared by any one of the preparation methods, wherein the chemical formula of the chiral organoboride is as follows:
wherein R is phenyl, p-chlorophenyl, 2-phenylethyl, o-methylphenyl or thienyl;
the specific preparation method comprises the following steps:
p1, according to the mass ratio 1 (1.2-2) (0.01-0.02) (0.01-0.03), taking alpha, beta-unsaturated ester (namely compound I in the reaction formula of the step P1), bisboronic acid pinacol ester, graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst and ligand (R, S) -josephos, adding an additive for pre-dissolution, and then adding water for mixing and stirring reaction for 2.5-6 hours at room temperature; filtering after the reaction is finished, and filtering filtrate and filter residue for later use; the additive is at least one of methanol, diethyl ether and toluene;
p2, purifying and drying the filtrate obtained in the step P1 to obtain pure chiral organoboride (namely a product II of a reaction formula in the step P1); and (3) washing and drying filter residues obtained in the step (P1), and recovering the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst for recycling.
It should be noted that in the step P1, α, β -unsaturated esters are a large class of organic compounds, and the chemical formula is as follows:
the α, β -unsaturated ester used in step P1 differs in that the R group may be phenyl, P-chlorophenyl, 2-phenylethyl, o-methylphenyl or thienyl. The corresponding chiral organoboride can be obtained by the above-mentioned method of the present invention, as long as the alpha, beta-unsaturated ester is used as a raw material. The additive used in the step P1 is any one or more of methanol, diethyl ether or toluene. The volume ratio of methanol, diethyl ether or toluene to the subsequently added water is preferably 1 (9-20).
The synthesis of alpha, beta-unsaturated esters can be carried out with reference to the literature (Catalytic Asymmetric Boration of Acyclic alpha, beta-Unsaturated Esters and Nitriles angelw.chem.2008, 120, 151-153); the reaction formula is as follows, and the product is characterized in terms of its structure by Nuclear Magnetic Resonance (NMR).
Taking toluene as an additive and the volume ratio of toluene to water added later being 1:9 as an example, the reaction formula of the step P1 is:
in the method provided by the invention, the pinacol ester of biboronic acid [ B ] 2 (pin) 2 ]Copper and boron intermediates are generated by the boron addition reaction with active center copper in the CS-GO-PVA-Cu catalyst and alpha, beta-unsaturated ester, enol copper intermediates are generated by the boron addition reaction, and the intermediate is rapidly protonated under the action of proton source water to generate boron addition products (namely chiral organic boride). The water in the reaction provides a proton source effect, so that the copper enol intermediate generates a target product in the protonation process, and the regeneration of the catalytic material is realized.
The ligand (R, S) -josephos used in step P1, named specifically (R) - (-) -1[ (S) -2- (diphenylphosphine) ferrocene ] ethyl dicyclohexylphosphine, is a commercially available product (available, for example, from Annaiji Corp.) having the following structural formula:
wherein Ph refers to phenyl and Cy refers to cyclohexane.
Preferably, the additive used in the step P1 is toluene, and the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst contains copper, wherein the copper is water, toluene=0.002 mmol (1.8-2) mL (0.1-0.2) mL.
It should be noted that the above-mentioned mmol and mL are relative concepts, and the use of the above-mentioned ratios is not limited to the use of 0.002mmol, (1.8-2) mL and (0.1-0.2) mL, as long as the volume relationship between the amount of copper in the CS-GO-PVA-Cu catalyst and the additive (toluene) is ensured to satisfy the above-mentioned requirements. Thus, the specific meaning to be expressed in the above-mentioned ratio of the amount is that, when toluene is used as the additive in the step P1, the volume ratio of toluene to (subsequently added) water is 1 (9-20), while also ensuring that the copper concentration in the CS-GO-PVA-Cu catalyst is 0.002mmol/2mL,1mmol/L, i.e., 1mM.
Preferably, in the step P1, the amount ratio of the substances of the alpha, beta-unsaturated ester I, the bisboronic acid pinacol ester, the copper in the copper oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst and the ligand (R, S) -joscihos is 1:1.2:0.01:0.01.
Preferably, in the step P1, the reaction is carried out for 3 hours at room temperature with mixing and stirring.
Preferably, step P2 is specifically: after the reaction is finished, filtering the reaction liquid, extracting the filtrate with ethyl acetate to obtain an organic phase containing chiral organoboride; the organic phase was treated with anhydrous Na 2 SO 4 Drying, filtering, removing ethyl acetate, purifying the obtained crude product by column chromatography to obtain chiral organoboride; and (3) washing and drying the filter residue obtained in the step (P1) to obtain the CS-GO-PVA-Cu catalyst.
As a conventional method, the recovery process of the CS-GO-PVA-Cu catalyst may specifically be selected as follows: and (3) washing the filter residue obtained in the step (P1) with an organic solvent (such as petroleum ether) for three times (3X 10 mL), and drying to remove the organic solvent, so that the CS-GO-PVA-Cu catalyst can be recovered for recycling.
More preferably, in step P2, the developing solvent used for column chromatography is petroleum ether and ethyl acetate in a volume ratio of (4-9): 1.
For performance testing of the final chiral organoboride, the chiral organoboride (i.e., product ii of the following reaction scheme) is further oxidized to the corresponding chiral hydroxy compound (i.e., compound iii of the following reaction scheme) by conventional methods in the art, and enantioselectivity measurement is performed to determine stereochemical configuration by comparing the optical rotation of the chiral hydroxy compound with that in the literature, the reaction scheme is as follows.
Compared with the prior art, the invention has the following advantages:
1. the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst provided by the invention has good biocompatibility, is environment-friendly, can be used for participating in pure water reaction, has a good effect of immobilized metallic copper, and has a longer service life; the method is simple and convenient to operate, can be very conveniently separated from other components in a reaction system by means of a solid-liquid separation method after the reaction is finished, greatly reduces the production cost, realizes repeated recycling of the CS-GO-PVA-Cu catalyst, and can obviously reduce various environmental pollution problems;
2. by using the graphene/chitosan/polyvinyl alcohol composite microsphere provided by the invention as a catalyst, a higher conversion rate of reactants can be realized only by using a lower dosage; the reaction condition is mild, no alkali is needed to be added, the reaction is carried out at room temperature, and the method is simple and easy to operate.
Drawings
FIG. 1 is an SEM spectrogram of a CS powder material, with a left image magnification of 2000 and a right image magnification of 3000;
FIG. 2 is an SEM spectrum of a CS-GO-PVA-Cu catalyst (GO content 0 wt%) at 2000 magnification in the left and 3000 magnification in the right;
FIG. 3 is an SEM spectrum of a CS-GO-PVA-Cu catalyst (GO content 2 wt%) at 2000 magnification in the left and 5000 magnification in the right;
FIG. 4 is an SEM spectrum of a CS-GO-PVA-Cu catalyst (GO content 4 wt%) at 2000 magnification in the left and 5000 magnification in the right;
FIG. 5 is an XRD spectrum of CS-GO-PVA-Cu catalyst; in the figure, the curve a is chitosan raw material, and the curves b, c and d are XRD spectra of solid powder after copper loading when the GO content in the first system is 0%, 2% and 4% respectively;
FIG. 6 is a TGA spectrum of CS-GO-PVA-Cu catalyst;
FIG. 7 is a physical diagram of CS-GO-PVA-Cu catalyst.
Detailed Description
The following description of the present invention will be made clearly and fully, and it is apparent that the embodiments described are only some, but not all, of the embodiments of the present invention. All other embodiments, which can be made by one of ordinary skill in the art without undue burden on the person of ordinary skill in the art based on embodiments of the present invention, are within the scope of the present invention.
In the following specific embodiments, if not specifically described, the preparation method of the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst (CS-GO-PVA-Cu catalyst) is carried out according to the following methods:
s1, preparing Graphene Oxide (GO), weighing 1.0g of Chitosan (CS), 0.18mL of acetic acid and 100mL of distilled water, putting into a flask, mixing uniformly, and magnetically stirring at room temperature for 12h; adding graphene oxide into a chitosan solution, and performing normal-temperature ultrasonic treatment (power is 50-100W, frequency is 28-40 kHz) for 20min to obtain a GO/CS homogeneous phase blending system;
then 50mg of polyvinyl alcohol and 1mL of glutaraldehyde are added, and then ultrasonic treatment is carried out at normal temperature (the power is 50-100W and the frequency is 28-40 kHz) for 30min, so that a GO/CS/PVA homogeneous phase blending system (namely a first system) containing graphene oxide with a specific mass fraction is prepared;
60mL of absolute ethyl alcohol, 12g of sodium hydroxide and 40mL of distilled water are added into a 250mL beaker, stirred to be colorless and transparent, and then cooled to room temperature to prepare a second system;
s2, dropwise adding the first system prepared in the step S1 into the second system by using a syringe with a capacity of 5mL to form microspheres; filtering, washing the microsphere with absolute ethanol for three times, washing with distilled water for three times, and drying at room temperature;
s3, adding the product prepared in the step S2 into a 100mL flask filled with 15mL of distilled water, soaking for 1h at 50 ℃, adding an excessive copper sulfate aqueous solution (prepared by 1g of copper sulfate pentahydrate and 10mL of distilled water), and stirring for reaction for 6h to adsorb copper ions; finally filtering and separating filter residues, washing with distilled water to remove free copper ions and sulfate ions, drying at 50 ℃ for 12 hours, and grinding to obtain the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst.
The preparation method of the graphene oxide used in the step S1 comprises the following steps:
s11, taking 4.0g of graphite flakes, 35mL of concentrated phosphoric acid (98% in mass fraction) and 350mL of concentrated sulfuric acid (98% in mass fraction), uniformly mixing, adding 5g of potassium permanganate every 10min, and adding 4 times, namely adding 20g of potassium permanganate in total;
s12, magnetically stirring the mixed system prepared in the step S11 at the constant temperature of 50 ℃ for 12 hours, and cooling to room temperaturePouring into ice until ice is dissolved, adding 30% H 2 O 2 And (3) obtaining solid Graphene Oxide (GO) after washing and drying until the aqueous solution is bright yellow. H 2 O 2 The amount of aqueous solution added is based on the bright yellow color of the final solution.
Test example 1: influence of graphene oxide content in first System on performance of CS-GO-PVA-Cu catalyst
Two sets of CS-GO-PVA-Cu catalysts were prepared, differing in that: in the first system prepared in the step S1, the mass fractions of the graphene oxide are respectively 2 weight percent and 4 weight percent, and are respectively marked as a test group and a test group.
In addition, CS powder material was taken as a control one and a control two, with no catalyst for graphene oxide added (i.e., CS-PVA-Cu catalyst). The only difference between the specific preparation methods is that the step S1 specifically comprises the following steps: 1.0g of Chitosan (CS), 0.18mL of acetic acid and 100mL of distilled water are weighed, put into a flask and mixed uniformly, and magnetically stirred for 12 hours at room temperature; then 50mg of polyvinyl alcohol and 1mL of glutaraldehyde are added, and ultrasonic treatment is carried out at normal temperature for 30min, so as to prepare a CS/PVA homogeneous blending system without graphene oxide;
60mL of absolute ethanol, 12g of sodium hydroxide and 40mL of distilled water were added to a 250mL beaker, stirred to be colorless and transparent, and then cooled to room temperature to prepare a second system. Subsequent processes such as microsphere preparation and the like remain unchanged, and finally the CS-PVA-Cu catalyst used for comparison is prepared.
By comparing the SEM characterization profile of the CS powder feedstock (fig. 1), the SEM characterization profile of the GO-free CS-PVA-Cu catalyst (fig. 2); SEM characterization of CS-GO-PVA-Cu catalyst with GO content of 2wt% (FIG. 3), and SEM characterization of CS-GO-PVA-Cu catalyst with GO content of 4wt% (FIG. 4), it can be found that:
(1) In fig. 1, the chitosan powder was in a flat state in comparison with the phase of a CS powder material of a group at an operating voltage of 5kv and a magnification of 500 and 5000 times.
(2) In FIG. 2, the solid powder of the CS-PVA-Cu catalyst of the control group two, without GO, was slightly coarser than the chitosan material at an operating voltage of 5kv, at a magnification of 2000 and 5000 times; few tiny particles attached to the surface, which indicates that copper ions are loaded successfully but with poor loading effect.
(3) In FIG. 3, at a GO content of 2% for the first system, the solid powder of the CS-GO-PVA-Cu catalyst tested in one group had a phase at an operating voltage of 5kv and a magnification of 2000 and 5000 times, which was significantly coarser than the chitosan feedstock; the slightly more surface-attached fine particles compared with fig. 2, shows that the copper ion loading was successful, but the loading effect was general.
(4) In FIG. 4, the solid powder of the CS-GO-PVA-Cu catalyst of the second group tested at a GO content of 4% for the first system had a phase at an operating voltage of 5kv and a magnification of 2000 and 5000 times, which was significantly coarser than the chitosan feedstock; compared with fig. 2, the surface of the copper ion carrier has more tiny particles, which indicates that the copper ion loading is successful; by comparison, white particles on the surface of the chitosan are copper which is loaded successfully, and the loading effect is optimal.
As shown in fig. 5, the XRD characterization patterns of the products of the comparative test one, two groups and the control one, two groups can be found: the XRD curve of b-d shows that compared with the chitosan powder, the diffraction peak of the graphene/chitosan/polyvinyl alcohol supported copper catalytic material at the same position is relatively low and wide because the hydrogen bond in the molecule changes after the material is complexed with copper, so that the crystallization performance is weakened, and the success of supporting bivalent copper is indicated. The d curve (test two groups) has the highest GO content, and excessive GO can coordinate with copper ions, so that more sharp crystallization peaks appear, and the effect of loading copper by CS-GO-PVA-Cu-2 is relatively good.
As shown in fig. 6, the TGA profile of the products of the comparison test one, two groups and the control one, two groups can be found: the CS-GO-PVA-Cu catalysts of the test group and the test group have two approximate weight losses from room temperature to 700 ℃, wherein the first weight loss of 30-100 ℃ is caused by detachment of water molecules from the body, and the second weight loss of 200-400 ℃ is the oxidative degradation of the macromolecular chain skeleton of the polymer. The residual copper ions in the CS-GO-PVA-Cu catalyst prepared in the second group are highest, so that the content of copper loaded in the CS-GO-PVA-Cu catalyst prepared finally is highest when the mass fraction of GO in the first system is 4%.
Test example 2: performance study of organoboride prepared with CS-GO-PVA-Cu catalyst
The specific preparation method of the organic boride comprises the following steps:
p1, 41mg of chalcone (Compound I), 60mg of B2 (pin) 2 5mg of the CS-GO-PVA-Cu catalyst prepared in test example 1 and 5.0mg of the ligand (R, S) -josephos are added into 0.2mL of toluene for pre-dissolution, 1.8mL of distilled water is added and stirred for 3 hours at room temperature, and asymmetric boration reaction of alpha, beta-unsaturated ester occurs, wherein the reaction equation is as follows:
wherein R is phenyl;
filtering after the reaction is finished, and filtering filtrate and filter residue for later use;
p2, the filtrate obtained in the step P1 is taken, purified and dried to obtain pure chiral organic boride (product II), and the specific method comprises the following steps: after the reaction, filtering the reaction solution, extracting the filtrate with ethyl acetate for three times (3X 10 mL) to obtain an organic phase containing chiral organoboride; the organic phase was treated with anhydrous Na 2 SO 4 Drying, filtering, rotary steaming, removing redundant ethyl acetate, purifying the obtained crude product by column chromatography to obtain chiral organic boride; taking filter residues obtained in the step P1, washing with petroleum ether for three times (3X 10 mL), drying to remove petroleum ether, and recycling the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst;
the chiral organoboride obtained in the above step P2 (product ii) was further converted into the corresponding chiral hydroxyl compound (compound iii) by oxidation for determination of enantioselectivity and determination of stereochemical configuration. The specific method comprises the following steps: into the chiral organoboride obtained in step P2244mg of sodium borate tetrahydrate and 5mL of a mixed solvent containing tetrahydrofuran and water are added, wherein the volume ratio of the tetrahydrofuran to the distilled water is 3:2; after 4h of reaction, the whole reaction system was filtered and extracted three times with ethyl acetate (3X 10 mL), and the organic phase was separated off and taken up in anhydrous Na 2 SO 4 Drying, filtering and rotary evaporating to remove solvent. Purifying the residue by petroleum ether/ethyl acetate mixed solvent (volume ratio of 5:1) column chromatography to obtain chiral hydroxyl compound (compound III); the reaction formula is as follows:
1. in step P1, the effect of the use of different additives on the boron addition reaction
Preparing a CS-GO-PVA-Cu catalyst by using a method of a test group II of a test example 1, and preparing a corresponding chiral organoboride according to the method, wherein the stirring reaction time of the step P1 is 3 hours; the only difference is that: the additives used in step P1 were 0.2mL of methanol, diethyl ether, toluene, acetone, respectively, and distilled water was subsequently added in an amount of 1.8mL. In addition, as a control group, only 2mL of distilled water was added without any additives. The yields and enantioselectivities (expressed in terms of ee values) of the chiral organoborides finally prepared are shown in table 1 below.
TABLE 1 results of investigation of the influence of different solvents on the boron addition reaction
It can be seen from Table 1 above that when the reaction time was 3 hours at the same time and the catalyst amount was 5mg at the same time, the effect of the change in the reaction solvent on the yield and the enantioselectivity (ee value) was remarkable. When toluene and water are used as solvents, the yield and ee value reach more than 90%, which indicates that the reaction effect is good; when methanol, water, diethyl ether and water are used as solvents, the yield and ee value are both over 80 percent, which indicates that the reaction effect is good; when only distilled water is added, the ee value reaches more than 80%, but the yield is low, and the conversion effect is poor; when acetone and water are used as solvents, the yield and ee value are low. This demonstrates that toluene and water are the best reaction solvents for the five aqueous solutions tested, with the same reaction time and catalyst amount.
2. Effect of the use of different CS-GO-PVA-Cu catalysts in step P1 on the boron addition reaction
Preparing a CS-GO-PVA-Cu catalyst by using a method of a test group II of a test example 1, preparing a corresponding chiral organoboride according to the method, stirring and reacting for 3 hours in the step P1, wherein the additive is 0.2mL of toluene, and then adding 1.8mL of distilled water; the only difference is that: the dosages of the CS-GO-PVA-Cu catalyst added in the step P1 are 1mg, 2.5mg, 5mg and 7.5mg respectively. In addition, the control group was prepared without adding any CS-GO-PVA-Cu catalyst in step P1. The yields and enantioselectivities (expressed in terms of ee values) of the chiral organoborides finally prepared are shown in Table 2 below.
TABLE 2 results of investigation of the effect of the amount of CS-GO-PVA-Cu catalyst on the boron addition reaction
As can be seen from the above Table 2, when toluene and water were used as solvents and the reaction time was 3 hours, changing the amount of the catalyst had a significant effect on the yield of chiral organoboride, but had little effect on the ee value, and the ee value of all of the five tests reached more than 90%. When the catalyst dosage is 0, the yield is only 37%; when the catalyst dosage is 1mg, the yield is only 43%; when the catalyst dosage is 2.5mg, the yield is only 47%; when the catalyst dosage is 5mg, the yield is 98%; the yield was only 98% at a catalyst level of 7.5mg. The addition of 7.5mg of catalyst was not evident as an improvement in yield over the amount of 5mg. Therefore, for economic reasons, a catalyst amount of 5mg is chosen as the most suitable catalyst amount.
3. In step P1, influence of the time of stirring reaction on the boron addition reaction
The CS-GO-PVA-Cu catalyst was prepared using the method of test two of test example 1, and the amount added was 5mg, 0.2mL of toluene was used as the additive for step P1, followed by 1.8mL of distilled water; and corresponding chiral organoboride is prepared according to the method, and the only difference is that: in the step P1, the reaction time after the CS-GO-PVA-Cu catalyst is added is respectively 0h, 1h, 2h, 3h and 4h. The yields and enantioselectivities (expressed in terms of ee values) of the chiral organoborides finally prepared are shown in Table 3 below.
TABLE 3 results of investigation of the influence of the reaction time on the boron addition reaction
As can be seen from Table 3, when the same amount of toluene (0.2 mL) and water (1.8 mL) were used as solvents and the catalyst amounts to 5mg, the reaction time was short, and the yield of the organoboride was significantly affected, but the ee value was extremely small, and the ee value of each of the five tests was 90% or more. When the reaction time is 0h, the reaction has not occurred yet; when the reaction time is 1h, the yield is only 25%, and the reaction is not complete; when the reaction time was 2h, the yield was 58%; when the reaction time is 3 hours, the yield is rapidly increased to 98%; when the reaction time is continuously increased to 4 hours, the yield reaches 99 percent, and almost complete conversion is realized. The yield of 4h reaction time was not significantly improved relative to 3h reaction time. Therefore, 3h is chosen as the optimal reaction time for saving time and cost.
According to the reaction result, the optimal condition of the prepared catalyst applied to the boron addition reaction is determined, namely 0.2mL of toluene is used as an additive, 1.8mL of distilled water is added, the reaction time is 3h, and the catalyst dosage is 5mg. The catalytic material is applied to boron addition reaction, under the condition of optimal reaction conditions, the yield is up to 98%, and the enantioselectivity value is also up to 95%, which shows that the graphene oxide/chitosan/polyvinyl alcohol composite copper catalyst has remarkable catalytic effect under the condition.
4. In step P1, the effect of the number of catalyst cycles on the boron addition reaction
The CS-GO-PVA-Cu catalyst was prepared using the method of test two group of test example 1, and the recycled catalyst was recovered in step P2 of test 2 in an amount of 5mg, 0.2mL of toluene was used as the additive for step P1, followed by 1.8mL of distilled water; the reaction time is 3h and corresponding chiral organic boride is prepared according to the method; the only difference is that: in the step P1, the CS-GO-PVA-Cu catalyst is added for recycling in the step P2 in the test 2, and the recycling times are respectively 0 times, 1 time, 2 times, 3 times, 4 times and 5 times, and the performance of the recycled catalyst is inspected. The yields and enantioselectivities (expressed in terms of ee values) of the chiral organoborides finally prepared are shown in Table 4 below.
TABLE 4 results of investigation of the effect of the number of catalyst cycles on the boron addition reaction
As can be seen from Table 4, when toluene 0.2mL and water 1.8mL were used as solvents, the catalyst amounts were 5mg as well, and the reaction times were 3 hours as well, the number of times the catalyst was recycled had little effect on the yield and enantioselectivity of the boron addition reaction. The catalyst which is not recycled and the catalyst which is recycled for 5 times are up to more than 90% in both yield and enantioselectivity, and almost complete conversion is achieved. The catalyst has obvious catalytic effect, good performance, and low cost.
The above detailed description describes in detail the practice of the invention, but the invention is not limited to the specific details of the above embodiments. Many simple modifications and variations of the technical solution of the present invention are possible within the scope of the claims and technical idea of the present invention, which simple modifications are all within the scope of the present invention.
Claims (10)
1. The preparation method of the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst is characterized by comprising the following steps of:
s1, preparing graphene oxide, adding the graphene oxide into a chitosan solution, and performing ultrasonic treatment at normal temperature for 15-60min; then adding polyvinyl alcohol and glutaraldehyde, and performing ultrasonic treatment at normal temperature for 30-60min to obtain a first system with the mass fraction of graphene oxide of 1-5%; adding absolute ethyl alcohol into a saturated sodium hydroxide aqueous solution, uniformly mixing, and cooling to room temperature to obtain a second system; the volume ratio of the saturated sodium hydroxide aqueous solution to the absolute ethyl alcohol is 4 (3-8);
s2, dripping the first system prepared in the step S1 into the second system to form microspheres, filtering, cleaning and drying at room temperature;
s3, soaking the product prepared in the step S2 in water at 40-80 ℃ for 1-2 hours, adding excessive copper sulfate aqueous solution, stirring for reaction, filtering to obtain filter residues, drying at 40-60 ℃ for 12-24 hours, and grinding to obtain the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst;
the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst is used for preparing chiral organic boride, and the chemical formula of the chiral organic boride is as follows:
wherein R is phenyl, p-chlorophenyl, 2-phenylethyl, o-methylphenyl or thienyl.
2. The preparation method of the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst according to claim 1, wherein in the step S1, the preparation method of the graphene oxide comprises the following steps:
s11, uniformly mixing graphite flakes, concentrated phosphoric acid and concentrated sulfuric acid, and quantitatively adding potassium permanganate in batches; the mass ratio of the graphite flake to the potassium permanganate is 1:5;
s12, stirring the mixed system prepared in the step S11 for 12-24 hours at 40-60 ℃, cooling to room temperature, pouring ice until the ice is dissolved, and adding H into the solution system 2 O 2 And (3) obtaining solid graphene oxide after washing and freeze drying until the aqueous solution is bright yellow.
3. The preparation method of the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst according to claim 1, wherein in the step S1, chitosan solution is prepared by mixing and stirring chitosan with the purity of 100-200mpa.s and acetic acid aqueous solution with the mass fraction of 6-8%, and the concentration of chitosan is 1-2g/mL.
4. The method for preparing the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst according to claim 1, wherein in the step S3, the concentration of the copper sulfate aqueous solution is 3-5mol/L.
5. The application of the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst prepared by the preparation method of claim 1 is characterized in that the catalyst is used for preparing chiral organoboride and has the chemical formula:
wherein R is phenyl, p-chlorophenyl, 2-phenylethyl, o-methylphenyl or thienyl;
the specific preparation method comprises the following steps:
p1, according to the mass ratio 1 (1.2-2) (0.01-0.02) (0.01-0.03), taking alpha, beta-unsaturated ester, bisboronic acid pinacol ester, the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst and ligand (R, S) -josephos, adding an additive for pre-dissolution, and then adding water for mixing and stirring reaction for 2.5-6 hours at room temperature; filtering after the reaction is finished, and filtering filtrate and filter residue for later use; the additive is at least one of methanol, diethyl ether and toluene;
p2, purifying and drying the filtrate obtained in the step P1 to obtain the pure chiral organoboride; and (3) washing and drying filter residues obtained in the step (P1), and recovering the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst for recycling.
6. The method according to claim 5, wherein the additive used in the step P1 is toluene, and the copper-containing copper-immobilized catalyst of the graphene oxide/chitosan/polyvinyl alcohol composite microsphere comprises water of toluene=0.002 mmol (1.8-2) mL (0.1-0.2) mL.
7. The use according to claim 5, wherein in step P1, the ratio of the amounts of the α, β -unsaturated ester, the bisboronic acid pinacol ester, the copper in the copper oxide/chitosan/polyvinyl alcohol composite microsphere supported copper catalyst and the ligand (R, S) -joscihos is 1:1.2:0.01:0.01.
8. The method according to claim 5, wherein in step P1, the water is added and the mixture is stirred at room temperature for a period of 3 hours.
9. The use according to claim 5, wherein step P2 is specifically: after the reaction is finished, filtering the reaction liquid, and extracting the filtrate with ethyl acetate to obtain an organic phase containing the chiral organoboride; the organic phase was treated with anhydrous Na 2 SO 4 Drying, filtering, removing ethyl acetate, purifying the obtained crude product by column chromatography to obtain the chiral organoboride; and (3) washing and drying the filter residue obtained in the step (P1), and recovering the graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst.
10. The use according to claim 9, wherein in step P2, the column chromatography is performed using a volume ratio (4-9) of petroleum ether to ethyl acetate of 1.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104386684A (en) * | 2014-12-16 | 2015-03-04 | 中国科学院宁波材料技术与工程研究所 | Preparation method of graphene and graphene |
| CN104588110A (en) * | 2014-12-23 | 2015-05-06 | 郑州轻工业学院 | Grapheme/chitosan/cuprous oxide composite material and preparation method and applications thereof |
| CN106902778A (en) * | 2017-04-28 | 2017-06-30 | 武汉理工大学 | A kind of chitosan/oxidized Graphene/polyvinyl alcohol cellular composite adsorbing material and preparation method thereof |
| WO2018004099A1 (en) * | 2016-06-27 | 2018-01-04 | 재단법인차세대융합기술연구원 | Graphene oxide/carbon nanotube composite fiber having heterojunction structure, and method for manufacturing graphene oxide/graphene composite fiber or graphene oxide/graphene/carbon nanotube composite fiber |
| CN110590820A (en) * | 2019-08-28 | 2019-12-20 | 湖北工程学院 | Process for preparing chiral organoboron compounds |
| CN112138719A (en) * | 2020-09-15 | 2020-12-29 | 绍兴文理学院 | Preparation method and application of layered graphene oxide composite film supported palladium catalyst |
| CN112321628A (en) * | 2020-11-27 | 2021-02-05 | 湖北工程学院 | Preparation method of beta-dimethylphenyl silicon substituted organic nitrile compound |
| CN113563370A (en) * | 2021-07-29 | 2021-10-29 | 湖北工程学院 | Preparation method for preparing beta-boryl ketone with substituent at alpha position by catalyzing chitosan loaded copper material |
| CN114262034A (en) * | 2021-12-31 | 2022-04-01 | 合肥工业大学 | Method for separating rubidium from salt lake brine by using polyvinyl alcohol/chitosan/graphene/nickel copper hexacyanide complex |
-
2022
- 2022-08-17 CN CN202210987224.0A patent/CN115634718B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104386684A (en) * | 2014-12-16 | 2015-03-04 | 中国科学院宁波材料技术与工程研究所 | Preparation method of graphene and graphene |
| CN104588110A (en) * | 2014-12-23 | 2015-05-06 | 郑州轻工业学院 | Grapheme/chitosan/cuprous oxide composite material and preparation method and applications thereof |
| WO2018004099A1 (en) * | 2016-06-27 | 2018-01-04 | 재단법인차세대융합기술연구원 | Graphene oxide/carbon nanotube composite fiber having heterojunction structure, and method for manufacturing graphene oxide/graphene composite fiber or graphene oxide/graphene/carbon nanotube composite fiber |
| CN106902778A (en) * | 2017-04-28 | 2017-06-30 | 武汉理工大学 | A kind of chitosan/oxidized Graphene/polyvinyl alcohol cellular composite adsorbing material and preparation method thereof |
| CN110590820A (en) * | 2019-08-28 | 2019-12-20 | 湖北工程学院 | Process for preparing chiral organoboron compounds |
| CN112138719A (en) * | 2020-09-15 | 2020-12-29 | 绍兴文理学院 | Preparation method and application of layered graphene oxide composite film supported palladium catalyst |
| CN112321628A (en) * | 2020-11-27 | 2021-02-05 | 湖北工程学院 | Preparation method of beta-dimethylphenyl silicon substituted organic nitrile compound |
| CN113563370A (en) * | 2021-07-29 | 2021-10-29 | 湖北工程学院 | Preparation method for preparing beta-boryl ketone with substituent at alpha position by catalyzing chitosan loaded copper material |
| CN114262034A (en) * | 2021-12-31 | 2022-04-01 | 合肥工业大学 | Method for separating rubidium from salt lake brine by using polyvinyl alcohol/chitosan/graphene/nickel copper hexacyanide complex |
Non-Patent Citations (1)
| Title |
|---|
| Fabrication of Chitosan/PVA/GO/CuO patch for potential wound healing application;K.S. Venkataprasanna et al.;《International Journal of Biological Macromolecules》;第143卷;第744-762页 * |
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