钴基仿生催化体系的设计及其在醛氧化酯化反应中的应用基础研究

By mimic the fantastic transformations achieved by biological processes, realizing aerobic oxidative esterification of aldehyde urgently required by production of the related bulk ester with atom economy and sustainable development consideration. The disadvantage of the current studied catalytic system such as heavy pollution, high costs, limited applicability, lead us to develop new protocol by implying cobalt as the active center, which was less prone before. Based on the rich oxidative-reductive valence of cobalt, the regulation of nitroxyl radicals in the oxidation, and Lewis acid/base tunability of each part, in this work, we will build a bionic coupled catalytic system for the high efficiency in transformation of aldehyde to ester by using molecular oxygen as the terminal oxidant, cobalt reagent or complexes as the catalyst and nitroxyl radicals as electron transfer mediator. First, carry out various stoichiometric reactions to study key scientific issues on oxidative dehydrogenation activity, the regeneration of catalytic center, activation of molecular oxygen and formation of the important intermediate during the reaction process. Second, obtain the influence of the coordinative bond property and the spatial structure of the active complex on the selectivity in terms of oxidative esterification of aldehydes, and a deep understanding of the regulatory mechanism of synergistic catalysis on the conversion rate, based on reaction kinetics and thermodynamic analysis. We hope to provide a certain scientific and theoretical basis for its promotion in the industrial applications by our efforts.

模拟生物氧化酶的有氧催化机制，将有机醛一步氧化成酯是生产大宗化工产品实现原子经济性以及适应可持续性发展的迫切需求。针对现有研究中污染重、成本高、适用性有限等问题，结合金属钴氧化还原价态丰富、氮氧自由基优越的单电子转移选择性以及各自可调的Lewis酸/碱性，本项目拟构建以氧气为氧源、金属钴有机试剂/配合物为催化剂、氮氧自由基为电子转移介质的耦合仿生催化体系用于醛到酯的高效氧化转化：开展化学计量反应以解决目标体系在脱氢氧化、活性催化中心再生、分子氧活化以及重要中间体形成中存在的关键科学问题；基于反应动力学、热力学数据，获得催化体系中配位键性质及空间结构对醛氧化酯化选择性的影响规律，深刻理解协同催化对转化率的调控机制，为其在工业应用上的推广提供科学依据和理论基础。

模拟生物氧化酶的有氧催化机制，将有机醛一步氧化成酯是生产大宗化工产品实现原子经济性以及适应可持续性发展的迫切需求。针对现有研究中污染重、成本高、适用性有限等问题，结合金属钴氧化还原价态丰富、氮氧自由基优越的单电子转移选择性以及各自可调的Lewis 酸/碱性，本项目构建了以氧气为氧源、金属钴有机试剂/配合物为催化剂、氮氧自由基为电子转移介质的耦合仿生催化体系用于醛到酯的高效氧化转化：开展了金属 Co 化合物与NO•自由基的配位性能研究；有机醛的氧化酯化自由基反应机理研究；Co/NO•催化的有机醛需氧氧化酯化反应的研究。基于反应动力学、热力学数据，获得催化体系中配位键性质及空间结构对醛氧化酯化选择性的影响规律，深刻理解协同催化对转化率的调控机制，为其在工业应用上的推广提供科学依据和理论基础。项目顺利完成了拟定的全部研究任务，共发表 SCI 论文 13 篇，申请专利 1 项，项目主持人在国际会议上作口头报告 2 次。