Tzouras Nikolaos V, Nahra Fady, Falivene Laura, Cavallo Luigi, Saab Marina, Van Hecke Kristof, Collado Alba, Collett Christopher J, Smith Andrew D, Cazin Catherine S J, Nolan Steven P
Department of Chemistry and Centre for Sustainable Chemistry, Ghent University, Krijgslaan 281,S-3, 9000, Ghent, Belgium.
Separation and Conversion Technology Unit, VITO (Flemish Institute for Technological Research), Boeretang 200, B-2400, Mol, Belgium.
Chemistry. 2020 Apr 6;26(20):4515-4519. doi: 10.1002/chem.202000564. Epub 2020 Mar 12.
We have been puzzled by the involvement of weak organic and inorganic bases in the synthesis of metal-N-heterocyclic carbene (NHC) complexes. Such bases are insufficiently strong to permit the presumed required deprotonation of the azolium salt (the carbene precursor) prior to metal binding. Experimental and computational studies provide support for a base-assisted concerted process that does not require free NHC formation. The synthetic protocol was found applicable to a number of transition-metal- and main-group-centered NHC compounds and could become the synthetic route of choice to form M-NHC bonds.
我们一直对弱有机碱和无机碱参与金属-N-杂环卡宾（NHC）配合物的合成感到困惑。这类碱的强度不足以在金属配位之前使假定所需的唑盐（卡宾前体）去质子化。实验和计算研究为一个无需游离NHC生成的碱辅助协同过程提供了支持。发现该合成方案适用于多种以过渡金属和主族为中心的NHC化合物，并且可能成为形成M-NHC键的首选合成路线。
