Cu/SiO2 catalysts prepared by the ammonia evaporation method were applied to hydrogenation of diethyl malonate to 1,3‐propanediol. The calcination temperature played an important role in the structural evolution and ...Cu/SiO2 catalysts prepared by the ammonia evaporation method were applied to hydrogenation of diethyl malonate to 1,3‐propanediol. The calcination temperature played an important role in the structural evolution and catalytic performance of the Cu/SiO2 catalysts, which were systematically characterized by N2 adsorption‐desorption, inductively coupled plasma‐atomic emission spectros‐copy, N2O chemisorption, X‐ray diffraction, Fourier transform infrared spectroscopy, H2 tempera‐ture‐programmed reduction, transmission electron microscopy, and X‐ray photoelectron spectros‐copy. When the Cu/SiO2 catalyst was calcined at 723 K, 90.7%conversion of diethyl malonate and 32.3%selectivity of 1,3‐propanediol were achieved. Compared with Cu/SiO2 catalysts calcined at other temperatures, the enhanced catalytic performance of the Cu/SiO2 catalyst calcined at 723 K can be attributed to better dispersion of copper species, larger cupreous surface area and greater amount of copper phyllosilicate, which results in a higher ratio of Cu＋/Cu0. The synergetic effect of Cu0 and Cu＋is suggested to be responsible for the optimum activity.展开更多
Based on the stability results of Radix hedysari extract, an unstable compound was extracted using acidic methanol and purified by rapid chromatographic methods successfully from Radix hedysari for the first time guid...Based on the stability results of Radix hedysari extract, an unstable compound was extracted using acidic methanol and purified by rapid chromatographic methods successfully from Radix hedysari for the first time guided by HPLC analysis. Its structure was identified as formononetin 7-O-β-D-（6＂-O-malonyl）-glucopyranoside by spectroscopic analyses.展开更多
Diethyl malonate being an initial raw material, processed with chlorination-replacement-desalination-vacuum rectification, is used to produce carbonyl diethyl malonate. An experiment for optimization determines that t...Diethyl malonate being an initial raw material, processed with chlorination-replacement-desalination-vacuum rectification, is used to produce carbonyl diethyl malonate. An experiment for optimization determines that the best reaction condition was： （1 reaction for 7 h at 10 ℃ with mole-ratio being 2.4 ＂ 1 between chloride and raw material （diethyl malonate）; （2 reaction for 4.5 h at 118 ℃ with mole-ratio being 1.2 ： 1 between the anhydrous sodium acetate and intermediate I. The final product carbonyl diethyl rnalonate recovery ratio reaches up to as high as 79.12% with a purity of 96.4%, which meets the market requirement. This synthesis technique has the advantages of simple process, moderate reaction conditions, high yield and low cost, being suitable for industrial scale production.展开更多
Highly efficient Michael addition reactions of malonates to nitroalkenes catalyzed by novel chiral thioureas derived from optically pure BINOL and amino acids are reported. Various trans-nitroalkenes reacted with malo...Highly efficient Michael addition reactions of malonates to nitroalkenes catalyzed by novel chiral thioureas derived from optically pure BINOL and amino acids are reported. Various trans-nitroalkenes reacted with malonates affording the desired products in up to 95% yield with excellent enantioselectivities （up to 97% ee）.展开更多
Ionic liquids （ILs） based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts （PTCs） for the base-promoted monoalkylatio...Ionic liquids （ILs） based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts （PTCs） for the base-promoted monoalkylation of diethyl malonate. The influence of various heterogeneous bases on yields was studied. Good yields and high selectivity were obtained. Solvent-free, mild reaction condition, short reaction time, and easy purification were the merits of this method. The catalytic system （IL-hase） could also be recycled after the extraction of products with ether.展开更多
A green synthesis route of diethyl malonate by palladium catalyzed carbonylation of ethyl chloroacetate in the presence of phase transfer agent is carried out under mild conditions in good yield. The effects of reacti...A green synthesis route of diethyl malonate by palladium catalyzed carbonylation of ethyl chloroacetate in the presence of phase transfer agent is carried out under mild conditions in good yield. The effects of reaction temperature and different bases on the yield of diethyl malonate are also discussed.展开更多
A novel method of preparing dimethyl malonate by carbonylation of methyl chloroacetate catalyzed by Na[Co(CO)(4)] was proposed. Na[Co(CO)(4)] was synthesized in situ in the presence of Na2S2O3 and iron powder. The eff...A novel method of preparing dimethyl malonate by carbonylation of methyl chloroacetate catalyzed by Na[Co(CO)(4)] was proposed. Na[Co(CO)(4)] was synthesized in situ in the presence of Na2S2O3 and iron powder. The effects of some reaction parameters such as temperature. CO pressure and the concentrations of catalyst on the yields of dimethyl malonate were discussed. The kinetic data were studied and a possible reaction mechanism was proposed.展开更多
Introduction 5-Monosubstituted isopropylidene malonates arc important synthetic organic intermediates. Since isopropylidene malonate has a stronger acidity （pK;=4.57）, its direct alkylation with alkyl halides usuall...Introduction 5-Monosubstituted isopropylidene malonates arc important synthetic organic intermediates. Since isopropylidene malonate has a stronger acidity （pK;=4.57）, its direct alkylation with alkyl halides usually gives 5,5-disubstitutcd isopropylidene malonates.展开更多
The condensation of aromatic aldehydes with isopropylidene malonate or 5,5-dimethyl-1,3-cyclohexanedione is carried out by DMF as solvent without catalyst.
An efficient enantioselective Michael addition of ethyl-2-cyanoacetate and diethyl malonate to α,β-unsaturated ketones catalyzed by a simple chiral Schiff base, and products were obtained in good yields at room temp...An efficient enantioselective Michael addition of ethyl-2-cyanoacetate and diethyl malonate to α,β-unsaturated ketones catalyzed by a simple chiral Schiff base, and products were obtained in good yields at room temperature.展开更多
Two novel copper complexes (<strong>1,2</strong>) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol a...Two novel copper complexes (<strong>1,2</strong>) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol at moderate temperature. These compounds were characterized by elemental analysis, UV-VIS, IR spectroscopies and powder X-ray diffraction analyses. Compound (<strong>1</strong>) melts at higher temperature (202°C) than compound (<strong>2</strong>) (100<span style="white-space:normal;">°</span>C). The IR spectra showed typical vibrations related to C=N and C=C, characteristic of pyrazolyl and pyridine ligands.展开更多
A series of malonate derivatives-calix[4]arene conjugates were synthesized through Knoevenagel condensation reaction between formyl-tetrapropoxycalix[4]arene and malonate derivatives. The structures of the resulting m...A series of malonate derivatives-calix[4]arene conjugates were synthesized through Knoevenagel condensation reaction between formyl-tetrapropoxycalix[4]arene and malonate derivatives. The structures of the resulting malonate derivative functionalized calix[4]arenes were characterized by NMR spectroscopy, mass spectrometry and even single crystal X-ray diffraction analysis.展开更多
Lanthanum malonate crystals were grown by single tube ionic diffusion through silica gel. The crystallinity of the grown crystals was analyzed by powder X-ray diffraction studies. Fourier transform infrared spectrosco...Lanthanum malonate crystals were grown by single tube ionic diffusion through silica gel. The crystallinity of the grown crystals was analyzed by powder X-ray diffraction studies. Fourier transform infrared spectroscopy （FTIR） and fourier transform （FT） Raman studies confirmed the presence of functional groups in the title compound. The optical band gap energy of the material was extracted from diffuse reflectance spectrum.展开更多
A new complex of malonic acid with lanthanum,La(Hmal)·(mal)·3H_2O,was synthesized and characterized by elemental analysis and IR spectra.The thermal decomposition process and their kinetic parameters n and E...A new complex of malonic acid with lanthanum,La(Hmal)·(mal)·3H_2O,was synthesized and characterized by elemental analysis and IR spectra.The thermal decomposition process and their kinetic parameters n and E_a were studied by means of TG and DTG.All of the intermediate and end products were determined and characterized by the mass loss in TG curve,elemental analysis and IR spectra.展开更多
Multicomponent alkene 1,2-dicarbofunctionalizations(DCFs)have emerged as a powerful strategy to rapidly incorporate both two carbon subunits across one C-C double bond in one step for enhancing molecular complexity an...Multicomponent alkene 1,2-dicarbofunctionalizations(DCFs)have emerged as a powerful strategy to rapidly incorporate both two carbon subunits across one C-C double bond in one step for enhancing molecular complexity and diversity.To the best of our knowledge,there is only one report on photoredox-catalyzed three-component DCFs with malonates through the radical−radical cross-coupling,while photoredox-catalyzed radical-polar crossover(RPC)-type DCFs with malonates were still rare.Herein,we describe a redox-neutral RPC-type 1,2-dialkylation of styrenes with malonates and aldehydes through the synergistic Brønsted base/photoredox catalysis system.This transition-metal-free strategy provides an efficient and clean approach to a broad variety ofδ-hydroxy esters and also features exceptionally mild conditions,wide compatibility of substrate scope and functional groups,and high atomic economy.Moreover,three-component 1,2-alkylacylation from the same starting materials was achieved in one-pot manner through such RPC-type coupling and subsequent two-electron oxidation process,providing a set ofδ-keto esters of interest in pharmaceutical research.展开更多
Binaphthyl sulfonimides have been developed to catalyze the asymmetric Michael addition of ketone to alky- lidene malonates, affording the corresponding Michael products in good to high yields （up to 98%） with good ...Binaphthyl sulfonimides have been developed to catalyze the asymmetric Michael addition of ketone to alky- lidene malonates, affording the corresponding Michael products in good to high yields （up to 98%） with good to excellent diastereoselectivity （up to 99 ; 1 dr） and enantioselectivity （up to 92% ee） under mild conditions using environmentally benign water as the solvent.展开更多
Myrtoidine and malagashanine,highly complex indole alkaloids,are effective adjuvants in developing cures for plasmodium malaria and potent multi-drug resistant agents.Despite nearly 30 years of progress,myrtoidine and...Myrtoidine and malagashanine,highly complex indole alkaloids,are effective adjuvants in developing cures for plasmodium malaria and potent multi-drug resistant agents.Despite nearly 30 years of progress,myrtoidine and the related family of Malagasy alkaloids still present formidable challenges for synthetic chemists.Here,we developed a diastereoselective[2+2+2]tandem cyclization reaction with alkyl-substituted methylene malonate,enabling highly efficient collective total synthesis of four Malagasy alkaloids from commercially available tryptamines within 10-13 steps.The synthetic strategy included rapid and highly stereoselective assembly of the tetracyclic indoline core containing 5-7 contiguous stereogenic carbon centers,rarely seen in indole alkaloids.Among the four natural products,(±)-myrtoidine,(±)-11-demethoxymyrtoidine,and(±)-12-hydroxymalagashanine were synthesized for the first time,and the work on(±)-malagashanine represented the shortest synthetic route so far.Our current study should enable further explorations of chemical and biological spaces based on myrtoidine,malagashanine,and related natural products.展开更多
Malonate is a high-value chemical that can be used to produce value-added compounds.Due to the toxic by-products and low product yield for malonate production through hydrolysis of cyanoacetic acid,microbial productio...Malonate is a high-value chemical that can be used to produce value-added compounds.Due to the toxic by-products and low product yield for malonate production through hydrolysis of cyanoacetic acid,microbial production methods have attracted significant attention.Previously,theβ-alanine pathway has been engineered in Escherichia coli for malonate production.In this study,theβ-alanine pathway was constructed in Saccharomyces cerevisiae by introducing the heterologous genes of BcBAPAT and TcPAND to convert l-aspartate to malonic semialdehyde,combining with co-expression genes of AAT2 and UGA2 to improve precursor supply and malonate producing.Through delta sequence-based integration of the two heterologous genes,the engineered strain produced with 7.21 mg/L malonate was screened.Further,replaced the succinic semialdehyde dehydrogenase gene UGA2 with yneI from E.coli which was utilized to produce malonate in previous study,increased the malonate titer to 7.96 mg/L in flask culture.Following optimization,fermentation of the final engineered strain in shake flasks yielded a maximum malonate titer of 12.83 mg/L,and this was increased to 91.53 mg/L during fed-batch fermentation in a 5 L bioreactor which increased by two-fold compared with that of the engineered strain overexpressing UGA2.展开更多
Triflumezopyrim(TFM)is a novel mesoionic pyrido[1,2-α]pyrimidinones insecticide,which acts on nicotinic acetylcholine receptors(n ACh Rs)and has no cross-resistance with other insecticides.Herein,we firstly developed...Triflumezopyrim(TFM)is a novel mesoionic pyrido[1,2-α]pyrimidinones insecticide,which acts on nicotinic acetylcholine receptors(n ACh Rs)and has no cross-resistance with other insecticides.Herein,we firstly developed a new continuous flow approach to synthesis 2-[3-(trifluoromethyl)phenyl]malonic acid,a key intermate of TFM,coupling with esterification,condensation,and hydrolysis.All three-step reactions were optimized and transformed into a continuous synthesis mode by three micro reaction units.Compared with the batch mode,the total reaction time and overall separation yield were improved from more than 12 h and 60%to 18 min and 73.38%,respectively.The solvent consumption and waste emission were significantly reduced,which also provides an eco-friendly and efficient potential tool for the development and production of mesoionic pyrido[1,2-α]pyrimidinones insecticide.展开更多
文摘Cu/SiO2 catalysts prepared by the ammonia evaporation method were applied to hydrogenation of diethyl malonate to 1,3‐propanediol. The calcination temperature played an important role in the structural evolution and catalytic performance of the Cu/SiO2 catalysts, which were systematically characterized by N2 adsorption‐desorption, inductively coupled plasma‐atomic emission spectros‐copy, N2O chemisorption, X‐ray diffraction, Fourier transform infrared spectroscopy, H2 tempera‐ture‐programmed reduction, transmission electron microscopy, and X‐ray photoelectron spectros‐copy. When the Cu/SiO2 catalyst was calcined at 723 K, 90.7%conversion of diethyl malonate and 32.3%selectivity of 1,3‐propanediol were achieved. Compared with Cu/SiO2 catalysts calcined at other temperatures, the enhanced catalytic performance of the Cu/SiO2 catalyst calcined at 723 K can be attributed to better dispersion of copper species, larger cupreous surface area and greater amount of copper phyllosilicate, which results in a higher ratio of Cu＋/Cu0. The synergetic effect of Cu0 and Cu＋is suggested to be responsible for the optimum activity.
基金National Natural Science Foundation of China (Grant No.20432030 and 20872006).
文摘Based on the stability results of Radix hedysari extract, an unstable compound was extracted using acidic methanol and purified by rapid chromatographic methods successfully from Radix hedysari for the first time guided by HPLC analysis. Its structure was identified as formononetin 7-O-β-D-（6＂-O-malonyl）-glucopyranoside by spectroscopic analyses.
基金Supported by the Innovation Fund for Technology Based Firms(10C26224212340)
文摘Diethyl malonate being an initial raw material, processed with chlorination-replacement-desalination-vacuum rectification, is used to produce carbonyl diethyl malonate. An experiment for optimization determines that the best reaction condition was： （1 reaction for 7 h at 10 ℃ with mole-ratio being 2.4 ＂ 1 between chloride and raw material （diethyl malonate）; （2 reaction for 4.5 h at 118 ℃ with mole-ratio being 1.2 ： 1 between the anhydrous sodium acetate and intermediate I. The final product carbonyl diethyl rnalonate recovery ratio reaches up to as high as 79.12% with a purity of 96.4%, which meets the market requirement. This synthesis technique has the advantages of simple process, moderate reaction conditions, high yield and low cost, being suitable for industrial scale production.
基金support from Natural Science Foundation of China(No.20772097)Sichuan Provincial Science Foundation for Outstanding Youth(No.05ZQ026-008)Key Project of the Education Department of Sichuan Province(No.2006A081).
文摘Highly efficient Michael addition reactions of malonates to nitroalkenes catalyzed by novel chiral thioureas derived from optically pure BINOL and amino acids are reported. Various trans-nitroalkenes reacted with malonates affording the desired products in up to 95% yield with excellent enantioselectivities （up to 97% ee）.
文摘Ionic liquids （ILs） based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts （PTCs） for the base-promoted monoalkylation of diethyl malonate. The influence of various heterogeneous bases on yields was studied. Good yields and high selectivity were obtained. Solvent-free, mild reaction condition, short reaction time, and easy purification were the merits of this method. The catalytic system （IL-hase） could also be recycled after the extraction of products with ether.
文摘A green synthesis route of diethyl malonate by palladium catalyzed carbonylation of ethyl chloroacetate in the presence of phase transfer agent is carried out under mild conditions in good yield. The effects of reaction temperature and different bases on the yield of diethyl malonate are also discussed.
文摘A novel method of preparing dimethyl malonate by carbonylation of methyl chloroacetate catalyzed by Na[Co(CO)(4)] was proposed. Na[Co(CO)(4)] was synthesized in situ in the presence of Na2S2O3 and iron powder. The effects of some reaction parameters such as temperature. CO pressure and the concentrations of catalyst on the yields of dimethyl malonate were discussed. The kinetic data were studied and a possible reaction mechanism was proposed.
基金Supported by the National Natural Science Foundation of Chinathe Basic Research Foundation of Zhejian Educational Commission.
文摘Introduction 5-Monosubstituted isopropylidene malonates arc important synthetic organic intermediates. Since isopropylidene malonate has a stronger acidity （pK;=4.57）, its direct alkylation with alkyl halides usually gives 5,5-disubstitutcd isopropylidene malonates.
文摘The condensation of aromatic aldehydes with isopropylidene malonate or 5,5-dimethyl-1,3-cyclohexanedione is carried out by DMF as solvent without catalyst.
基金We appreciate the National Natural Science Foundation of China （No. 20962018, 20862015, 20762009 and 20562011） for supporting this research.
文摘An efficient enantioselective Michael addition of ethyl-2-cyanoacetate and diethyl malonate to α,β-unsaturated ketones catalyzed by a simple chiral Schiff base, and products were obtained in good yields at room temperature.
文摘Two novel copper complexes (<strong>1,2</strong>) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol at moderate temperature. These compounds were characterized by elemental analysis, UV-VIS, IR spectroscopies and powder X-ray diffraction analyses. Compound (<strong>1</strong>) melts at higher temperature (202°C) than compound (<strong>2</strong>) (100<span style="white-space:normal;">°</span>C). The IR spectra showed typical vibrations related to C=N and C=C, characteristic of pyrazolyl and pyridine ligands.
基金Financial support from the National Natural Science Foundation of China (No. 21371177) is acknowledged
文摘A series of malonate derivatives-calix[4]arene conjugates were synthesized through Knoevenagel condensation reaction between formyl-tetrapropoxycalix[4]arene and malonate derivatives. The structures of the resulting malonate derivative functionalized calix[4]arenes were characterized by NMR spectroscopy, mass spectrometry and even single crystal X-ray diffraction analysis.
文摘Lanthanum malonate crystals were grown by single tube ionic diffusion through silica gel. The crystallinity of the grown crystals was analyzed by powder X-ray diffraction studies. Fourier transform infrared spectroscopy （FTIR） and fourier transform （FT） Raman studies confirmed the presence of functional groups in the title compound. The optical band gap energy of the material was extracted from diffuse reflectance spectrum.
基金Project supported by the National Natural Science Foundation of China
文摘A new complex of malonic acid with lanthanum,La(Hmal)·(mal)·3H_2O,was synthesized and characterized by elemental analysis and IR spectra.The thermal decomposition process and their kinetic parameters n and E_a were studied by means of TG and DTG.All of the intermediate and end products were determined and characterized by the mass loss in TG curve,elemental analysis and IR spectra.
基金supported by the National Natural Science Foundation of China(Nos.22101237,22171233)the Science and Technology Program of Sichuan Province(No.2022NSFSC1219)+1 种基金the Science and Technology Program of Luzhou City(Nos.2021-SYF-34,2023LZXNYDJ019)and the Open Project Program of Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province(No.HYX21003).
文摘Multicomponent alkene 1,2-dicarbofunctionalizations(DCFs)have emerged as a powerful strategy to rapidly incorporate both two carbon subunits across one C-C double bond in one step for enhancing molecular complexity and diversity.To the best of our knowledge,there is only one report on photoredox-catalyzed three-component DCFs with malonates through the radical−radical cross-coupling,while photoredox-catalyzed radical-polar crossover(RPC)-type DCFs with malonates were still rare.Herein,we describe a redox-neutral RPC-type 1,2-dialkylation of styrenes with malonates and aldehydes through the synergistic Brønsted base/photoredox catalysis system.This transition-metal-free strategy provides an efficient and clean approach to a broad variety ofδ-hydroxy esters and also features exceptionally mild conditions,wide compatibility of substrate scope and functional groups,and high atomic economy.Moreover,three-component 1,2-alkylacylation from the same starting materials was achieved in one-pot manner through such RPC-type coupling and subsequent two-electron oxidation process,providing a set ofδ-keto esters of interest in pharmaceutical research.
基金Acknowledgment We are grateful for financial support from the National Natural Science Foundation of China （No. 21072020）, the Science and Technology Innovation Program of Beijing Institute of Technology （No. 2011CX01008） and the Development Program for Distinguished Young and Middle-aged Teachers of Beijing Institute of Technology.
文摘Binaphthyl sulfonimides have been developed to catalyze the asymmetric Michael addition of ketone to alky- lidene malonates, affording the corresponding Michael products in good to high yields （up to 98%） with good to excellent diastereoselectivity （up to 99 ; 1 dr） and enantioselectivity （up to 92% ee） under mild conditions using environmentally benign water as the solvent.
基金This research was made possible as a result of a generous grant from the National Natural Science Foundation of China(NSFC,grant nos.21772224 and 91956103).
文摘Myrtoidine and malagashanine,highly complex indole alkaloids,are effective adjuvants in developing cures for plasmodium malaria and potent multi-drug resistant agents.Despite nearly 30 years of progress,myrtoidine and the related family of Malagasy alkaloids still present formidable challenges for synthetic chemists.Here,we developed a diastereoselective[2+2+2]tandem cyclization reaction with alkyl-substituted methylene malonate,enabling highly efficient collective total synthesis of four Malagasy alkaloids from commercially available tryptamines within 10-13 steps.The synthetic strategy included rapid and highly stereoselective assembly of the tetracyclic indoline core containing 5-7 contiguous stereogenic carbon centers,rarely seen in indole alkaloids.Among the four natural products,(±)-myrtoidine,(±)-11-demethoxymyrtoidine,and(±)-12-hydroxymalagashanine were synthesized for the first time,and the work on(±)-malagashanine represented the shortest synthetic route so far.Our current study should enable further explorations of chemical and biological spaces based on myrtoidine,malagashanine,and related natural products.
基金supported by the National Key R&D Program of China(2019YFA0905502)the National Natural Science Foundation of China(21877053)+1 种基金Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-KJGG-015)the Open Foundation of Jiangsu Key Laboratory of Industrial Biotechnology(KLIB-KF201807).
文摘Malonate is a high-value chemical that can be used to produce value-added compounds.Due to the toxic by-products and low product yield for malonate production through hydrolysis of cyanoacetic acid,microbial production methods have attracted significant attention.Previously,theβ-alanine pathway has been engineered in Escherichia coli for malonate production.In this study,theβ-alanine pathway was constructed in Saccharomyces cerevisiae by introducing the heterologous genes of BcBAPAT and TcPAND to convert l-aspartate to malonic semialdehyde,combining with co-expression genes of AAT2 and UGA2 to improve precursor supply and malonate producing.Through delta sequence-based integration of the two heterologous genes,the engineered strain produced with 7.21 mg/L malonate was screened.Further,replaced the succinic semialdehyde dehydrogenase gene UGA2 with yneI from E.coli which was utilized to produce malonate in previous study,increased the malonate titer to 7.96 mg/L in flask culture.Following optimization,fermentation of the final engineered strain in shake flasks yielded a maximum malonate titer of 12.83 mg/L,and this was increased to 91.53 mg/L during fed-batch fermentation in a 5 L bioreactor which increased by two-fold compared with that of the engineered strain overexpressing UGA2.
基金the National Key Research and Development Program of China(Nos.2023YFD1700303,2022YFD17800)National Natural Science Foundation of China(Nos.21878088,21476077)for financial support。
文摘Triflumezopyrim(TFM)is a novel mesoionic pyrido[1,2-α]pyrimidinones insecticide,which acts on nicotinic acetylcholine receptors(n ACh Rs)and has no cross-resistance with other insecticides.Herein,we firstly developed a new continuous flow approach to synthesis 2-[3-(trifluoromethyl)phenyl]malonic acid,a key intermate of TFM,coupling with esterification,condensation,and hydrolysis.All three-step reactions were optimized and transformed into a continuous synthesis mode by three micro reaction units.Compared with the batch mode,the total reaction time and overall separation yield were improved from more than 12 h and 60%to 18 min and 73.38%,respectively.The solvent consumption and waste emission were significantly reduced,which also provides an eco-friendly and efficient potential tool for the development and production of mesoionic pyrido[1,2-α]pyrimidinones insecticide.
