{"title":"偕胺肟纤维Pd配合物催化的连续流Heck偶联反应","authors":"Jiaxin Xie, Siyu Lu, Yilin Zhang, Xiaohan Lu, Z. Ding, Ting-xian Tao, Maodong Xu, Zhichuan Wu","doi":"10.1177/17475198231157010","DOIUrl":null,"url":null,"abstract":"Improving production efficiency and developing green catalytic systems are key issues for applying Heck coupling reactions in the chemical industry. In this study, an amidoxime-fiber-supported Pd catalyst is prepared from polyacrylonitrile fiber, hydroxylamine hydrochloride, and PdCl2. The morphology and structure of amidoxime-fiber-supported Pd are characterized by scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectrometer, X-ray diffraction, and inductively coupled plasma-optical emission spectrometer. A packed-bed flow reactor is designed and employed for catalysis of the Heck reaction of iodobenzene and styrene based on the amidoxime-fiber-supported Pd catalyst. The effects of reaction temperature, flow rate, cycle time, and reactant concentration on the conversion and yield are investigated. The results show that the optimal conditions for the continuous-flow single reactor are 70 °C, iodobenzene concentration of 30 mmol L−1 in a solution of N,N-dimethylformamide (100 mL) under continuous flow at a flow rate of 2 mL min−1. The catalyst showed good activity and stability after a continuous operation time of 50 h, with catalytic activity 2.21 times higher than that obtained with traditional batch reaction. Furthermore, we have established a new flow reaction system based on the numbering-up of reactors with a parallel connection. The catalytic efficiency of four parallel reactors is four times higher than that of a single reactor. Kinetic studies reveal that the reaction has low activation energy (8.8771 kJ mol−1), indicating that amidoxime-fiber-supported Pd has good catalytic activity. This research provides an alternative pathway for highly efficient Heck coupling in continuous flow.","PeriodicalId":15318,"journal":{"name":"Journal of Chemical Research-s","volume":"80 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Continuous-flow Heck coupling reactions catalyzed by Pd complexes of amidoxime fibers\",\"authors\":\"Jiaxin Xie, Siyu Lu, Yilin Zhang, Xiaohan Lu, Z. Ding, Ting-xian Tao, Maodong Xu, Zhichuan Wu\",\"doi\":\"10.1177/17475198231157010\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Improving production efficiency and developing green catalytic systems are key issues for applying Heck coupling reactions in the chemical industry. In this study, an amidoxime-fiber-supported Pd catalyst is prepared from polyacrylonitrile fiber, hydroxylamine hydrochloride, and PdCl2. The morphology and structure of amidoxime-fiber-supported Pd are characterized by scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectrometer, X-ray diffraction, and inductively coupled plasma-optical emission spectrometer. A packed-bed flow reactor is designed and employed for catalysis of the Heck reaction of iodobenzene and styrene based on the amidoxime-fiber-supported Pd catalyst. The effects of reaction temperature, flow rate, cycle time, and reactant concentration on the conversion and yield are investigated. The results show that the optimal conditions for the continuous-flow single reactor are 70 °C, iodobenzene concentration of 30 mmol L−1 in a solution of N,N-dimethylformamide (100 mL) under continuous flow at a flow rate of 2 mL min−1. The catalyst showed good activity and stability after a continuous operation time of 50 h, with catalytic activity 2.21 times higher than that obtained with traditional batch reaction. Furthermore, we have established a new flow reaction system based on the numbering-up of reactors with a parallel connection. The catalytic efficiency of four parallel reactors is four times higher than that of a single reactor. Kinetic studies reveal that the reaction has low activation energy (8.8771 kJ mol−1), indicating that amidoxime-fiber-supported Pd has good catalytic activity. 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引用次数: 0
摘要
提高生产效率和发展绿色催化体系是Heck偶联反应在化工领域应用的关键问题。本研究以聚丙烯腈纤维、盐酸羟胺和PdCl2为原料,制备了偕胺肟纤维负载钯催化剂。利用扫描电镜、能量色散谱、x射线光电子能谱、x射线衍射和电感耦合等离子体发射能谱对偕胺肟-纤维负载Pd的形貌和结构进行了表征。设计了一种以偕胺肟-纤维负载Pd为催化剂的填充床流动反应器,用于催化碘苯和苯乙烯的Heck反应。考察了反应温度、流量、循环时间和反应物浓度对转化率和产率的影响。结果表明,在N,N-二甲基甲酰胺(100 mL)溶液中,以70°C、碘苯浓度为30 mmol L−1,流速为2 mL min−1的连续流动条件下,单反应器的最佳条件为连续流动。催化剂在连续运行50 h后表现出良好的活性和稳定性,催化活性是传统间歇反应的2.21倍。此外,我们还建立了一种新的基于反应器编号和并联的流动反应系统。4个并联反应器的催化效率比单个反应器高4倍。动力学研究表明,该反应具有较低的活化能(8.8771 kJ mol−1),表明偕胺肟纤维负载Pd具有良好的催化活性。该研究为连续流中高效Heck耦合提供了另一种途径。
Continuous-flow Heck coupling reactions catalyzed by Pd complexes of amidoxime fibers
Improving production efficiency and developing green catalytic systems are key issues for applying Heck coupling reactions in the chemical industry. In this study, an amidoxime-fiber-supported Pd catalyst is prepared from polyacrylonitrile fiber, hydroxylamine hydrochloride, and PdCl2. The morphology and structure of amidoxime-fiber-supported Pd are characterized by scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectrometer, X-ray diffraction, and inductively coupled plasma-optical emission spectrometer. A packed-bed flow reactor is designed and employed for catalysis of the Heck reaction of iodobenzene and styrene based on the amidoxime-fiber-supported Pd catalyst. The effects of reaction temperature, flow rate, cycle time, and reactant concentration on the conversion and yield are investigated. The results show that the optimal conditions for the continuous-flow single reactor are 70 °C, iodobenzene concentration of 30 mmol L−1 in a solution of N,N-dimethylformamide (100 mL) under continuous flow at a flow rate of 2 mL min−1. The catalyst showed good activity and stability after a continuous operation time of 50 h, with catalytic activity 2.21 times higher than that obtained with traditional batch reaction. Furthermore, we have established a new flow reaction system based on the numbering-up of reactors with a parallel connection. The catalytic efficiency of four parallel reactors is four times higher than that of a single reactor. Kinetic studies reveal that the reaction has low activation energy (8.8771 kJ mol−1), indicating that amidoxime-fiber-supported Pd has good catalytic activity. This research provides an alternative pathway for highly efficient Heck coupling in continuous flow.
期刊介绍:
The Journal of Chemical Research is a peer reviewed journal that publishes full-length review and research papers in all branches of experimental chemistry. The journal fills a niche by also publishing short papers, a format which favours particular types of work, e.g. the scope of new reagents or methodology, and the elucidation of the structure of novel compounds. Though welcome, short papers should not result in fragmentation of publication, they should describe a completed piece of work. The Journal is not intended as a vehicle for preliminary publications. The work must meet all the normal criteria for acceptance as regards scientific standards. Papers that contain extensive biological results or material relating to other areas of science may be diverted to more appropriate specialist journals. Areas of coverage include: Organic Chemistry; Inorganic Chemistry; Materials Chemistry; Crystallography; Computational Chemistry.