Halikowska-Tarasek Katarzyna, Ochędzan-Siodłak Wioletta, Dziuk Błażej, Szostak Roman, Szostak Michal, Bisz Elwira
Department of Chemistry and Pharmacy, Opole University, 48 Oleska Street, Opole 45-052, Poland.
Department of Chemistry, Wroclaw University of Science and Technology, Norwida 4/6, Wroclaw 50-373, Poland.
Inorg Chem. 2025 Apr 28;64(16):7851-7857. doi: 10.1021/acs.inorgchem.5c01013. Epub 2025 Apr 15.
N-Heterocyclic carbenes (NHCs) have been established as the predominant ligand class in inorganic and organometallic chemistry. Simultaneously, there has been a major interest in dinuclear ligands, where cooperative effects between the metal centers have been widely exploited across numerous research avenues. Herein, we report the synthesis of dinuclear sterically hindered and adaptable N-heterocyclic ligands based on the modular IPr* framework. These ligands are distinguished by (1) the bridging group between the N-heterocyclic carbene donors and (2) the steric and electronic characteristics of the N-aromatic wingtips. The net effect is a remarkably broadly ranging steric environment around the metal center (%V of 33.9 up to 60.4%) as well as versatile conformation ranging from the perfectly linear (3.2°) to almost fully perpendicular (79.3°) between the carbene donors. The ligands have been evaluated in the gold(I)-catalyzed hydration and carboxylation of alkynes, where they show enhanced catalytic reactivity over mononuclear gold(I) complexes. Considering the importance of dinuclear N-heterocyclic carbenes across different research fields, we expect that this ligand class will be of broad interest in inorganic and organometallic chemistry.
N-杂环卡宾（NHCs）已成为无机化学和有机金属化学中占主导地位的配体类型。与此同时，人们对双核配体产生了浓厚兴趣，金属中心之间的协同效应已在众多研究领域中得到广泛应用。在此，我们报告了基于模块化IPr*框架合成的双核位阻且适应性强的N-杂环配体。这些配体的特点在于：（1）N-杂环卡宾供体之间的桥连基团；（2）N-芳基翼尖的空间和电子特性。其综合效应是在金属中心周围形成了范围极为广泛的空间环境（%V值从33.9到60.4%），以及卡宾供体之间从完全线性（3.2°）到几乎完全垂直（79.3°）的多样构象。这些配体已在金（I）催化的炔烃水合和羧化反应中进行了评估，结果表明它们比单核金（I）配合物具有更高的催化活性。鉴于双核N-杂环卡宾在不同研究领域的重要性，我们预计这类配体将在无机化学和有机金属化学中引起广泛关注。
