Martynova Ekaterina A, Tzouras Nikolaos V, Pisanò Gianmarco, Cazin Catherine S J, Nolan Steven P
Department of Chemistry and Centre for Sustainable Chemistry, Ghent University, Building S3, Krijgslaan 281, 9000 Gent, Belgium.
Chem Commun (Camb). 2021 Apr 25;57(32):3836-3856. doi: 10.1039/d0cc08149c. Epub 2021 Mar 26.
N-Heterocyclic carbenes (NHCs) are nowadays ubiquitous in organometallic chemistry and catalysis. Recently, a synthetic method which makes use of weak bases and desirable solvents has emerged as a simple, widely applicable and cost-effective pathway to well defined M-NHC complexes. Herein, recent studies devoted to the weak base approach are examined in detail, in order to showcase the simplicity, scope and variations of the method with regards to the azolium salts, bases and the metal sources, as well as the reaction conditions used. Mechanistic investigations are presented, illustrating the formation of intermediates which are air and moisture stable, prior to the metallation step. Finally, the importance, limitations and future prospects of the weak base route are discussed.
N-杂环卡宾（NHCs）如今在有机金属化学和催化领域无处不在。最近，一种利用弱碱和理想溶剂的合成方法已成为一种简单、广泛适用且具有成本效益的途径，用于制备结构明确的M-NHC配合物。本文详细研究了近期致力于弱碱方法的研究，以展示该方法在唑鎓盐、碱、金属源以及所用反应条件方面的简单性、适用范围和变化。文中还介绍了机理研究，阐明了在金属化步骤之前形成的对空气和水分稳定的中间体。最后，讨论了弱碱路线的重要性、局限性和未来前景。
