铁基碳材料的制备及其在合成含氮杂环化合物中的应用

【作者】 王飞；

【导师】 林雅玫； 马晶晶；

【作者基本信息】 南京师范大学 ， 生物与医药（专业学位）， 2023， 硕士

【摘要】 含氮杂环化合物在药物化学、生物化学等学科中至关重要,占美国食品药品管理局批准的所有药物的近50%。在各类含氮杂环化合物中,喹唑啉和吡咯类化合物具有抗炎、抗菌、抗氧化剂和抗癌活性等广泛的生物活性,受到了特别的关注。另一方面,铁是最丰富的过渡金属,具有分布广泛,价格低廉且对环境无害等特点。铁的价态在-2～+5之间,具有较强的氧化还原性能、Lewis酸性以及配位能力。此外,铁结合生物酶在体内可以参与许多重要的转化。铁的这些特征使其成为替代贵金属的绝佳候选者,并在其他非贵金属中脱颖而出。碳材料因为具有良好的导电性和热稳定性,较高的机械稳定性和低密度等独特的物理化学特性,被认为是最佳的非均相载体。因此,将铁和碳材料的优势有效结合的铁基碳材料有望成为一种高效、可持续的有机合成催化剂,进而用于含氮杂环化合物的合成。本论文通过浸渍法和自组装法制备了两种不同的前体,通过一锅热解的方法制备得到两种不同的铁基碳材料,并系统研究了其在合成喹唑啉类化合物和吡咯类化合物中的催化性能。研究内容如下:首先,通过浸渍法制备了一种由氮掺杂碳层包裹的铁基碳材料Fe-Fe O_x@NC,并研究其在水相中催化合成喹唑啉类化合物的性能。研究发现,由于氮掺杂碳层包裹的保护作用,使得纳米铁颗粒具有较强的抗毒化能力,是催化性能较高的主要原因。其极佳催化反应条件为:反应溶剂为水,时间为24 h,温度为130℃,氧化剂为空气中的氧气,喹唑啉类化合物的收率在62%-99%之间。其次,通过自组装法合成了一种氮硅共掺杂的铁基碳材料Fe@NSi C,并将该材料应用于催化级联反应合成吡咯类化合物。其中,硅掺杂可以增加Fe@NSi C的Lewis酸性位点数量和铁物种的电子密度,显著提高了Fe@NSi C的催化活性。其极佳催化反应条件为:反应时间为24 h,温度为100℃,无水甲酸用量为5 mmol,1,8-二氮杂二环十一碳-7-烯用量为1.50 mmol,吡咯类化合物的收率在55%-94%之间。该合成方法同时具备多个优点,包括无溶剂条件,催化剂可回收使用及适用底物广泛等,为有机合成中复杂目标化合物的合成提供了新的路径。更多还原

【Abstract】 Nitrogen-containing heterocyclic compounds are critical in pharmaceutical chemistry,biochemistry and other disciplines,accounting for nearly 50 percent of all drugs approved by the U.S.Food and Drug Administration.Among all kinds of nitrogen-containing heterocyclic compounds,quinazoline and pyrrole compounds have a wide range of biological activities such as anti-inflammatory,antibacterial,antioxidant and anticancer activities,and have received special attention.Iron,on the other hand,is the most abundant transition metal and is widely distributed,cheaply and environmentally sound.Iron has a valence state between-2and+5,and has strong redox properties,Lewis acidity and coordination ability.Iron-based enzymes are involved in lots of vital transformations in vivo.These characteristics of iron make it an excellent candidate to replace precious metals and stand out from other non-precious metals.Carbon material is considered as the best heterogeneous carrier because of its unique physical and chemical characteristics such as good electrical conductivity and thermal stability,high mechanical stability and low density.Therefore,iron-based carbon materials that effectively combine the advantages of iron and carbon materials are expected to be an efficient and sustainable catalyst for organic synthesis,which can be used for the synthesis of nitrogen-containing heterocyclic compounds.In this paper,two different precursors were prepared by impregnation method and self-assembly method,and then two different iron-based carbon materials were prepared by one-pot pyrolysis.Their catalytic properties in the synthesis of quinazoline compounds and pyrrole compounds were systematically studied.The research contents are as follows:Firstly,an iron-based carbon material Fe-Fe O_x@NC coated with nitrogen doped carbon layer was prepared by impregnation method,and its catalytic synthesis of quinazoline compounds in aqueous phase was investigated.It was found that the protective effect of nitrogen doped carbon coating made the iron nanoparticles have strong anti-toxicity ability,which is the main reason for the high catalytic performance.The optimum catalytic conditions were as follows:the reaction solvent was water,the time was 24 h,the temperature was 130℃,the oxidant was oxygen in the air,and the yield of quinazoline compounds was between 62%and 99%.Secondly,a nitrogen silicon co-doped iron-based carbon material Fe@NSi C was synthesized by self-assembly method,and the material was used to catalyze the cascade reaction synthesis of pyrrole compounds.Silicon doping can increase the number of Lewis acid sites at Fe@NSi C and the electron density of iron species,and significantly improve the catalytic activity of Fe@NSi C.The optimum catalytic conditions were as follows:reaction time was 24 h,temperature was 100℃,dosage of anhydrous formic acid was 5 mmol,dosage of 1,8-diazacyclodecundecan-7-ene was 1.50 mmol,and the yield of pyrrole compounds was 55%-94%.This synthesis method has many advantages,including solvent-free condition,recyclable catalyst and wide range of applicable substrates,etc.,which provides a new path for the synthesis of complex target compounds in organic synthesis.更多还原