Journal of Flow Chemistry
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2018
·Vol. 8
·期 1
·29-34
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IF 1.658
Yu Jiangang,Xu Jianguo,Li Jie,Jin Yi,Xu Wanghui,Yu Zhiqun,Lv Yanwen
A two-step flow reactor has been set up for an expeditious synthesis of 4-benzylidene-pyrazol-5-one derivatives. This procedure involved cyclization of aromatic hydrazine/ β -keto ester and subsequent Knoevenagel condensation reaction with aromatic aldehydes in tandem without isolation of intermediates. Residence time was reduced to less than 2 min in total through conducting this reaction at a relatively high temperature. Accordingly, 15 samples were achieved and isolated in moderate to excellent yields.
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研究领域:
有机化学
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药物化学
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DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 40
·27865-27872
·
IF 3.9
Fan Wang,Shuai Zhang,Congxia Xie,Xin Jin
Herein, based on the concept of integration of phosphine ligands and ionic liquids (ILs), a class of chiral phosphine-functionalized polyether ionic liquids (CPF-PILs) were synthesized by ion-exchange reaction between polyether imidazolium ILs and a phenyl-sulfonated (S)-(−)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) chiral diphosphine ligand, and employed in the Ru-catalyzed homogeneous asymmetric hydrogenation of β-keto esters. The resulting CPF-PILs combined the dual functions of the chiral phosphine ligand and ILs, allowing efficient recovery and recycling of the chiral catalysts using only a catalytic amount of CPF-PILs. The effects of various factors, including the chiral catalyst structure, solvent properties, reaction temperature, hydrogen pressure, and hydrobromic acid dosage, on catalytic performance were thoroughly investigated, as well as the cycling stability and universality of the chiral catalysts were examined. The findings of the present study demonstrated that, under optimal reaction conditions, the model substrate methyl acetoacetate underwent quantitative conversion to methyl β-hydroxybutyrate with a 97% enantiomeric excess (ee). The chiral catalyst used in this process can be recycled up to 12 times and showed good applicability to structurally various β-keto esters. The present study presents a novel approach for using ILs in asymmetric hydrogenation reactions in an environmentally friendly manner.
研究领域:
化学
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催化
·
绿色化学
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DOI
PubMed
高影响因子
Molecular Catalysis
·
2021
·
IF 5.062
Xin Jin,Sen Huang,Fan Wang,Lin Zhu,Hongbing Song,Congxia Xie,Shitao Yu,Shumei Li
2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) is a widely used chiral phosphine ligand, and the sulfonated BINAP is one of the important water-soluble BINAP derivatives. In this article, we report an improved oleum sulfonation method for the synthesis of the high-purity 5,5′-disulfonato-( S )-BINAP ligand with an industrially acceptable high yield. By optimizing the sulfonation conditions and improving the workup process, the yield of 5,5′-disulfonated products was enhanced to 73 %. Furthermore, an acetonitrile extraction protocol was developed for the purification of sulfonated products by efficiently removing phosphine oxides, by which the content of phosphine oxide can be controlled below 3 %. The structure of 5,5′-disulfonato-( S )-BINAP was characterized with the elemental analysis, FT-IR, 1 H NMR, 13 C NMR, 31 P NMR, 1 H- 1 H COSY, 1 H- 13 C HSQC, 1 H- 13 C HMBC, and HR-MS, which unambiguously confirmed that the sulfo groups are introduced at the 5,5′-position of the binaphthyl ring skeleton in ( S )-BINAP. The prepared high-purity 5,5′-disulfonato-( S )-BINAP was evaluated in the Ru-catalyzed asymmetric hydrogenation of β -keto esters, which exhibited high catalytic activity, enantioselectivity and excellent catalytic stability.
研究领域:
有机化学
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催化化学
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DOI
高影响因子
Polymers
·
2025
·Vol. 17
·期 7
·870
·
IF 4.9
Yanfei Wu,Min Han,Xianrong Shen,Qingping Song,Dongdong Liu,Wei Zhang
Amphiphilic block copolymers are essential for developing advanced polymer nanomaterials with applications in bioimaging, drug delivery, and nanoreactors. In this study, we successfully synthesized functional block copolymer assemblies at high concentrations through redox-initiated reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization of 2-(acetoacetoxy)ethyl methacrylate (AEMA), a β -ketoester functional monomer. Utilizing a redox initiation system at 50 °C, we produced poly(poly(ethylene glycol) methyl ether methacrylate)- b -PAEMA (PPEGMA n -PAEMA m ). Kinetic studies demonstrated rapid monomer conversion exceeding 95% within 30 min, with distinct polymerization phases driven by micelle formation and monomer depletion. Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS) revealed the formation of diverse morphologies, including worm-like, vesicular structures, and spherical micelles, depending on the macro-CTA molecular weight and monomer concentration. Additionally, post-polymerization modification with aggregation-induced emission (AIE) luminogens, such as 1-(4-aminophenyl)-1,2,2-tristyrene (TPE-NH 2 ), resulted in AIE-active polymer assemblies exhibiting strong fluorescence in aqueous dispersions. These AIE-active polymer assemblies also exhibited good biocompatibility. These findings demonstrate the efficacy of redox-initiated RAFT emulsion polymerization in fabricating functional, scalable block copolymer assemblies with potential applications in the field of life sciences.
研究领域:
高分子化学
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纳米材料科学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Lin-Fu Xie,Wan-Hong Huang,Jian-Ping Chen,Hai-Lin Chen,Cheng Hou,Qing-Ling Ni,Ting-Hong Huang,Liu-Cheng Gui,Xiu-Jian Wang
Photocatalytic selective oxidation plays an important role in developing green chemistry. However, it is challenging to design an efficient photocatalyst for controlling the selectivity of photocatalytic oxidation reaction and exploring its detailed mechanism. Here, we synthesized three conjugated microporous polymers (CMPs) with D-A structures, named M−SATE−CMPs (M Zn, Cu and Co), with different d-band centers based on different metal centers, resulting in the discrepancy in adsorption and activation capacities for the reactants, which produces the selectivity of β-keto esters being catalyzed into α-hydroperoxide β-keto esters (ROOH) or to α-hydroxyl β-keto esters (ROH). Density functional theory (DFT) calculations also demonstrate that the adsorption and activation capacities of the metal active centers in M−SATE−CMPs (M Zn, Cu and Co) for ROOH are the key factors to influence the photocatalytic selective oxidation of β-keto ester. This study provides a promising strategy for designing a metallaphotoredox catalyst whose photocatalytic selectivity depends on the d-band center of metal site in the catalyst.
研究领域:
化学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2020
·Vol. 21
·期 5
·1709
·
IF 4.556
Juan Guo,Huan Guo,Jin Liu,Fangrui Zhong,Yuzhou Wu
Manganese oxidizing bacteria can produce biogenic manganese oxides (BMO) on their cell surface and have been applied in the fields of agriculture, bioremediation, and drinking water treatment to remove toxic contaminants based on their remarkable chemical reactivity. Herein, we report for the first time the synthetic application of the manganese oxidizing bacteria,Pseudomonas putidaMnB1 as a whole-cell biocatalyst for the effective oxidation of β-keto ester with excellent yield. Differing from known chemical protocols toward this transformation that generally necessitate the use of organic solvents, stoichiometric oxygenating agents and complex chemical catalysts, our strategy can accomplish it simply under aqueous and mild conditions with higher efficiency than that provided by chemical manganese oxides. Moreover, the live MnB1 bacteria are capable of continuous catalysis for this C-O bond forming reaction for several cycles and remain proliferating, highlighting the favorable merits of this novel protocol for sustainable chemistry and green synthesis.Keywords:Pseudomonas putidaMnB1;biogenic manganese oxides;abiotic manganese oxides;α-Hydroxy-β-keto esters;whole-cell biocatalysis
研究领域:
生物催化
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绿色化学
·
有机合成
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环境生物技术
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DOI
PubMed
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Xiangyu Zheng,Zhe Dou,Wenqiang Xiang,Wen Zhang,Ye Ni,Guochao Xu
N -substituted β-amino esters as an important class of chiral amines, are widely used as building blocks in pharmaceuticals. A novel imine reductase Sv IRED was identified through gene mining from Streptomyces viridochromogenes with high enantioselectivity of > 99 % ee (1 R , 2 S ), 95 % de ( cis:trans ), towards 2-oxocyclohexane-1-carboxylate and cyclopropylamine. Sv IRED exhibited the highest activity at pH 7.0 and 40 °C. A variety of amine donors could be used by Sv IRED and produce chiral N -substituted β-amino esters with different enantioselectivity. Employing methylamine ( i ) and pyrrolidine ( n ) as amine donors, Sv IRED exhibited reversed enantioselectivity of 23 % ee (1 S , 2 R ) and 79 % ee (1 S , 2 R ) respectively. Through alanine scanning, M183 and H244 were identified with remarkable roles in governing enantioselectivity towards i and n . Compared with WT Sv IRED, the enantioselectivity of M183A was inverted to ee value of >99 % (1 R , 2 S ) and de value of >99 % ( cis:trans ) towards i , and the enantioselectivity of H244A was inverted to ee value of 88 % (1 R , 2 S ) and de value of >99 % ( cis:trans ) towards n . Interaction analysis indicated the orientation of ester group was vital for manipulation of enantioselectivity. This study provides novel Imine reductase mutants for enantioselective synthesis of N -substituted β -amino esters with different amine donors.
研究领域:
生物化学
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生物催化
·
酶工程
·
手性合成
·
药物化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）