自组装协同催化高选择性合成卤代芳烃

Regioselectively Synthesis of Halogenated Arenes via Self-Assembly and Synergistic Catalysis Strategy

卤代芳烃是非常重要的合成砌块,广泛应用于农用化学品、材料和药物等的合成。芳烃的亲电取代卤化反应是制备芳基卤化物最简单的方法,但是富电子芳烃的卤化反应存在区域选择性差的挑战。本实验采用自组装协同催化策略,以环己基苯溴化反应为模型反应,高选择性合成溴代芳烃,进而应用于卤代芳烃的高选择性合成。在加深学生芳烃亲电取代卤化反应的同时,也向学生传授自组装、协同催化和路易斯酸碱催化等重要知识,加深学生对亲电取代反应机理和离子型中间体的了解。实验主要由卤代芳烃的合成、机理探究及实验普适性三部分组成,包含多种有机实验基本操作,涉及反应监测、分离纯化、产物表征等多个重要环节,实验整体时长7小时,安全性高,可操作性强,适合本科实验教学开设。本实验秉持科研反哺教学的理念,将新的科研成果转化为人才培养内容,有助于提高学生的科研创新与实践能力。

Electrophilic halogenation of arenes represents a fundamental method for synthesizing aryl halides,crucial in the construction of various agrochemicals,materials,and pharmaceuticals.However,achieving regioselectivity in the halogenation of electron-rich arenes has posed a persistent challenge.This experiment demonstrates a synergistic catalytic approach for halogenating arenes bearing electron-donating substituents under mild conditions,offering a highly selective pathway to aryl halides.The utilization of hydrogen bonding between a Brønsted acid and the protic solvent nitromethane facilitates this transformation,effectively addressing the aforementioned challenge.The experiment not only enhances students’understanding of electrophilic halogenation reactions of arenes but also imparts knowledge on self-assembly,synergistic catalysis,and Lewis acid-base catalysis.Furthermore,it deepens students’comprehension of reaction mechanisms and ionic intermediates.The experiment comprises three main components:synthesis of brominated aromatics,mechanism exploration,and applicability assessment.It encompasses various organic laboratory techniques,including reaction monitoring,purification,and product characterization.With a duration of 7 hours and ensuring high safety,this experiment is suitable for undergraduate teaching.Moreover,it serves to strengthen students’fundamental experimental skills while fostering their capacity for scientific research innovation and practice,preparing them for future scientific endeavors.