Department of Chemistry, Warsaw University, Zwirki i Wigury Street 101, 02-089 Warsaw, Poland.
Dalton Trans. 2013 May 28;42(20):7354-8. doi: 10.1039/c2dt32856a.
Two ruthenium-based pre-catalysts containing an ionic tag covalently connected to a N-heterocyclic carbene (NHC) ligand are reported. These novel complexes, bearing a polar benzimidazolium group, are air-stable and can be easily prepared from commercially available reagents. The quaternary benzimidazolium tag allows the efficient separation of ruthenium waste from the metathesis product after reaction. Application in several olefin metathesis transformations leads to desired products of high purity, which exhibit ruthenium contamination levels as low as 1 ppm after simple filtration through a pad of silica gel.
报道了两种含有离子标记的钌前催化剂，该离子标记通过共价键与 N-杂环卡宾（NHC）配体相连。这些新型配合物带有极性苯并咪唑基团，在空气中稳定，可由市售试剂轻松制备。季铵苯并咪唑标记允许在反应后从复分解产物中有效分离钌废物。在几种烯烃复分解转化中的应用得到了高纯度的目标产物，在简单地通过硅胶垫过滤后，其钌污染水平低至 1ppm。
