CarBoRu - Anionic Carbenes and Borylanions: Tuning the properties of ruthenium complexes in olefin metathesis

n -杂环碳化合物（NHCs）在有机金属催化领域有着重要的影响。由于它们具有很强的西格玛供体特征，它们能够削弱M-L键与其他西格玛结合的共配体在反位（反影响）中的作用，并更好地稳定在大多数催化循环中形成的低配位活性物质。当NHC结构被赋予负电荷时，这些效应甚至会增强，负电荷提供阴离子碳或硼阴离子（基于碳原子C与B-的等电子关系）。采用这一最新的概念，本提案的作者已经证明了高活性的Au， Ir和pd催化体系的例子。鉴于ru催化烯烃反应对C=C键形成的重要性和广泛范围，基于此提议将引入-1电荷的催化剂调整策略扩展到ru催化的反应。

N-heterocyclic carbenes (NHCs) exerted a strong impact on the area of organometallic catalysis. Due to their strong sigma-donor character they are capable of weakening the M-L bond to other sigma-bound co-ligands in trans-position (trans-influence) and better stabilize low-coordinate active species, which are formed in most catalytic cycles. These effects are even expected to be enhanced when the NHC architectures are endowed with negative charges, which either affords anionic carbenes or boryl anions (based on the isoelectronic relationship of a carbon atom C to B-). Employing this very recent concept, the authors of this proposal have demonstrated examples of Au-, Ir- and Pd-catalyzed systems of high activity. In view of the importance and the wide scope of Ru-catalyzed olefin metathesis for C=C bond formations, the strategy of catalyst tuning by the introduction of -1 charges will be expanded to Ru-catalyzed cmetathesis based on this proposal.