摘要
N-取代吲哚是一类重要的杂环化合物,在医药、功能化材料、有机液体储氢等领域有着广泛应用.本工作采用共沉淀法合成了一系列类水滑石催化剂,首次实现了非贵金属催化乙二醇和N-取代苯胺为原料一步合成y-取代吲哚的方法.研究了通过改变元素组成对催化活性的影响,得到催化剂Ni1.5Zn1.5Al1的活性最高,其中Ni元素为主要活性组分起催化作用,Zn元素可协同Ni元素促进反应发生.通过X射线衍射(XRD)、热重分析(TGA)、电感耦合等离子发射光谱(ICP-OES)和N2物理吸附分析(BET)对Ni/Zn/Al系列催化剂进行了结构与组成的分析.所提供的合成方案能够有效地应用于不同类型N-取代吲哚的合成.与现有方法相比,摆脱了贵金属的限制,且催化剂在经历5次循环后仍能保持良好的催化活性,具有原料价格低、生产成本低、操作工艺简单、环境友好、原子利用率高等优点.
Abstract
Indole derivatives are an extremely important class of heterocyclic compounds with extensive applications in fields such as medicine and biology.In recent years,with the development of organic liquid hydrogen storage technology,its application scope has been continuously expanding.There have been many reports on the synthesis of indole,among which the synthesis of monosubstituted indole mainly involves direct halogenation of indole and direct cyclization of aromatic amines and alcohols.The former requires a large amount of halogenated reagents and excessive inorganic salts,resulting in poor environmental compatibility.The latter is a very ideal synthesis method with advantages such as high atomic efficiency and environmental friendliness,but currently all reported cases require the participation of precious metals.Therefore,the development of inexpensive non precious metal catalysts based on biomass ethylene glycol as raw material for the synthesis of N-substituted indole compounds has important scientific research significance and application value in large-scale produc-tion and application in the fields of medicine and hydrogen energy.In the current study,a series of hydrotalcite like catalysts using the coprecipitation method were prepared and applied in the one-step synthesis of N-substituted indoles using ethylene glycol and N-substituted anilines.By changing the elemental composition of hydrotalcite like catalysts,the optimal elemental composition was selected as Ni1.5Zn1.5Al1,with Ni as the main active component playing a catalytic role,Zn element can synergistically promote the reaction with Ni element,while aluminum element is a structural maintenance component without catalytic activity.The structure and composition of Ni/Zn/Al hydrotalcite catalysts were analyzed by X-ray diffraction(XRD),thermogravimetric analysis(TGA),inductively coupled plasma-optical emission spectrometer(ICP-OES),and N2 physical adsorption analysis(BET),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).This strategy can be effectively applied to N-alky l and aryl indole derivatives.Compared with reported methods,it overcomes the limitations of precious metals,and the catalyst can maintain good catalytic activity after five cycles.It has the advantages of low raw material price,low production cost,simple operation process,friendly environment and high atomic utilization rate.
基金项目
中国石油天然气集团有限公司基础性前瞻性科技专项(2023ZZ1205)
四川省科技计划(2021ZYCD005)
西南石油大学自然科学项目(2021JBGS07)
维普
万方数据