Carbene- and phosphine-substituted Biradicaloids for sustainable Catalysis (CarPhoSCat)

用于可持续催化的卡宾和膦取代的双自由基 (CarPhoSCat)

• 批准号: 531749456
• 负责人: Dr. Peter Coburger
• 金额: --
• 依托单位: Lehrstuhl für Anorganische Chemie mit Schwerpunkt Neue Materialien
• 依托单位国家: 德国
• 项目类别: Independent Junior Research Groups
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/531749456?language=en
• 关键词: Carbene; phosphine; substituted; Biradicaloids; sustainable

Due to their environmental and economical implications, there is an ongoing interest to replace noble metals in homogeneous catalysis by their more earth-abundant 3d counterparts (base metals) or to mimic the behaviour of transition metals using main-group element compounds. For this purpose, the development of specialized ligand systems is necessary. Generally, these can be divided into two categories: redox-active ligands in which the ligand itself participates in electron-transfer processes, thus enabling the typical two-electron redox-steps associated with precious metal catalysts and ligands with strongly basic sites which assist in heterolytic cleavage of covalent bonds in the substrates (cooperative bond activation). Despite the many impressive achievements using these two concepts, homogeneous main-group and base metal catalysts are often inferior in terms of activity and selectivity in comparison with noble metal catalysts. The goal of the CarPhoSCat research project is to address and overcome some of the limitations by the development of main-group and base metal catalysts with carbene- and phosphine-substituted biradicaloid ligands. Such ligands feature strong metal-ligand interactions, support redox-activity, flexible coordination modes and additionally carry Lewis-basic sites. The CarPhoSCat project is divided into two branches: 1) The application of group 13 and 14 complexes in Lewis-acid and cooperative catalysis, and 2) the development of catalytically active manganese, iron and cobalt carbonyl complexes and their application in olefin metathesis. Branch 1 develops cationic complexes of biradicaloid ligands with a strong electrophilicity and are thus expected to show improved performance in hydroelementation reactions compared to established Lewis-acids. Furthermore, these cationic complexes are valuable starting materials to prepare cooperative catalysts. The targeted catalytic processes are the hydrogenation of olefins and the dehydropolymerization of amine and phosphine boranes. In later stages of the project, the insight gained from the catalytic hydrogenation reactions with the cooperative catalysts will be used to tackle even more challenging transformations such as hydrohydroxylations and hydroaminations using ammonia. Branch 2 of the CarPhoSCat project deals with the synthesis of manganese, iron and cobalt carbonyl complexes of biradicaloids. These compounds are promising starting materials for the preparation of various catalytically active, low-coordinate base metal complexes. The emphasis will be on alkylidene complexes which are active in olefin metathesis. The strong metal-ligand interactions and the possibility of fine tuning the electronic and steric properties within the biradicaloid complexes will be beneficial for this project.

由于它们的环境和经济影响，在均相催化中用它们在地球上更丰富的3d对应物（贱金属）代替贵金属或使用主族元素化合物来模拟过渡金属的行为是一个持续的兴趣。为此，开发专门的配体系统是必要的。通常，这些可以分为两类：氧化还原活性配体，其中配体本身参与电子转移过程，从而实现与贵金属催化剂相关的典型的两电子氧化还原步骤，以及具有强碱性位点的配体，其有助于底物中共价键的异裂（协同键活化）。尽管使用这两种概念取得了许多令人印象深刻的成就，但均相主族和贱金属催化剂与贵金属催化剂相比在活性和选择性方面往往较差。CarPhoSCat研究项目的目标是通过开发具有卡宾和膦取代的双自由基配体的主族和贱金属催化剂来解决和克服一些限制。这种配体具有强的金属-配体相互作用，支持氧化还原活性，灵活的配位模式，并额外携带路易斯碱性位点。CarPhoSCat项目分为两个分支：1）第13和14族配合物在路易斯酸和协同催化中的应用，2）催化活性锰，铁和钴羰基配合物的开发及其在烯烃复分解中的应用。分支1开发了具有强亲电性的双自由基配体的阳离子络合物，因此与已建立的路易斯酸相比，预期在水元素化反应中显示出改进的性能。此外，这些阳离子配合物是制备协同催化剂的有价值的起始材料。目标催化过程是烯烃的氢化以及胺和膦硼烷的脱氢聚合。在该项目的后期阶段，从协同催化剂的催化氢化反应中获得的见解将用于解决更具挑战性的转化，例如使用氨的氢羟基化和氢胺化。CarPhoSCat项目的分支2涉及合成锰、铁和钴的双自由基羰基络合物。这些化合物是制备各种催化活性的低配位贱金属配合物的有希望的起始材料。重点将放在烯烃复分解反应中的亚烷基配合物上。强金属配体相互作用和微调的电子和空间性质的biradicaloid配合物的可能性将有利于这个项目。