Exploration of Abnormal N-Heterocyclic Carbene Nickel and Copper Complexes (aNiCu)

异常N-杂环卡宾镍铜配合物（aNiCu）的探索

• 批准号: 422677511
• 负责人: Privatdozent Dr. Rajendra S. Ghadwal
• 金额: --
• 依托单位: Arbeitsgruppe Anorganische Chemie und Strukturchemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/422677511?language=en
• 关键词: Exploration; Abnormal; Heterocyclic; Carbene; Nickel

Classical N-heterocylic carbenes (NHCs), 1,3-imidazol-2-ylidenes, are very versatile σ-donor ligands that have led to remarkable advances in organometallic chemistry and catalysis. The widespread success of NHCs is mainly due to their stronger σ-donor ability compared to traditional phosphine ligands. Experimental and theoretical data suggest that abnormal NHCs (aNHCs) (1,3-imidazol-4-ylidenes or 1,3-imidazol-5-ylidenes) are even stronger σ-donors than classical NHCs, perhaps the strongest carbon-donor neutral ligands known till date. Despite their enormous potential in catalysis and beyond, stable aNHC-complexes (particularly with late 3d-metals) are very scarce and most of the reported compounds are serendipitous products. Therefore, the development of rational synthetic methods for aNHC-complexes and their exploration is important and highly desired. This project aims at the synthesis of aNHC-Cu and aNHC-Ni complexes and the exploration of their structure, reactivity, and potential catalytic applications. The proposed synthetic methodologies rely on the use of C2-arylated imidazolium salts, which are readily accessible by the catalytic C2-arylation of NHCs. These salts are promising precursors for the synthesis of aNHCs and functionalized aNHCs. Three sets of ligands namely aNHCs, functionalized aNHCs, and ditopic cabanionic aNHCs (dc-aNHCs) will be investigated. Syntheses of a series of Cu- and Ni-complexes, including heterobimetallic derivatives, are strategic. Reactivity studies of the proposed compounds with small molecules such as CO2, P4, and organic substrates aim to accomplish a fundamental understanding of their “structure-reactivity relationship”, which will be used to uncover their potential applications in catalytic synthesis.

经典的N-杂环卡宾，1，3-咪唑-2-亚甲基，是用途非常广泛的σ供体配体，在有机金属化学和催化方面取得了显著的进展。NHC的广泛成功主要是因为与传统的膦配体相比，它们具有更强的σ供体能力。实验和理论数据表明，反常NHC(1，3-咪唑-4-亚甲基或1，3-咪唑-5-亚甲基)是比经典NHC更强的σ供体，可能是迄今已知的最强的碳供体中性配体。尽管ANHC-络合物在催化和其他领域具有巨大的潜力，但稳定的ANHC-络合物(特别是晚期3D金属)非常稀少，而且大多数报道的化合物都是偶然的产物。因此，开发合理的ANHC-络合物的合成方法及其探索是非常重要和迫切的。本项目旨在合成ANHC-铜和ANHC-Ni络合物，并探索它们的结构、反应活性和潜在的催化应用。拟议的合成方法依赖于C2-芳基咪唑盐的使用，这些盐很容易通过NHC的C2-芳基化反应获得。这些盐是合成aNHCs和功能化aNHCs的很有前途的前体。将研究三组配体，即aNHCs、官能化aNHCs和双位碳阴离子aNHCs(DC-aNHCs)。合成一系列铜和镍的配合物，包括异双金属衍生物，具有战略意义。对所提出的化合物与小分子如二氧化碳、P4和有机底物的反应性研究旨在从根本上了解它们的“结构-反应关系”，这将被用来揭示它们在催化合成中的潜在应用。