Ruthenium-based organometallic

Many different metal catalysts have been explored for racemization of secondary alcohols. Among them, ruthenium-based organometallic complexes have been most intensively tested as the racemization catalyst (Figure 1.1). 

Although B12 seems to be a complicated biomolecule, it is a very versatile carrier for robust organometallic compounds for various purposes. Our finding implies to use, e.g., ruthenium-based agents along the same line, concealing it behind the Bi2 framework and release in the intracellular space. 

Phosphinocarbene or 2 -phosphaacetylene 4, which is in resonance with an ylide form and with a form containing phosphoms carbon triple bond, is a distillable red oil. Electronic and more importantly steric effects make these two compounds so stable. Carbene 4 adds to various electron-deficient olefins such as styrene and substituted styrenes. Bertrand et al. have made excellent use of the push-pull motif to produce the isolable carbenes 5 and 6, which are stable at low temperature in solutions of electron-donor solvents (THF (tetrahydrofuran), diethyl ether, toluene) but dimerizes in pentane solution. Some persistent carbenes are used as ancillary ligands in organometallic chemistry and in catalysis, for example, the ruthenium-based Grubbs catalyst and palladium-based catalysts for cross-coupling reactions. 

The Ru(in) compounds [HIm][trans-RuCl4(Im)(DMSO-5)] and [HInd][tran5-RuCl4(Ind)2] (Im = imidazole, Ind = indazole, Eig. 22.22) have completed phase I clinical trials as anti-cancer drugs. The former complex selectively targets metastases of solid tumours. The range of ruthenium-based compounds that exhibits anti-cancer activity includes organometallic ruthenium(II) complexes. ... 

In summary, the organometallic approach is also efficient to prepare bimetallic nanoparticles. By precisely selecting the reaction conditions (precursor, stabilizer, reactant), we could access to ruthenium-based bimetallic nanoparticles displaying a controlled chemical order, i.e. alloy, core-shell, or even nanoparticles decorated with a second metal such as platinum, iron, or tin. These nanoparticles, which display different surface properties, can pave the way towards synergetic and selective catalytic performances. 

The outstanding performances of five-membered NHC ligands in organometallic chemistry and catalysis prompted Grubbs and co-workers to develop a novel stable four-membered NHC [64]. Following their interest in developing new ruthenium olefin metathesis catalysts, they synthesised and fully characterised complex 51 to study the impact of the architecturally unique NHC ligand on the activity of the Ru-based catalyst [65] (Fig. 3.20). In the RCM of 1 at 40°C in CH Cl with 51 (5 mol% catalyst), the reaction reached completion within 20 min, whereas less than 10 min are required for standard catalysts 14 and 16. It should be noted that catalysts 14 and 16 are able to complete the RCM of 1 with only 1 mol% catalyst at 30°C. 

Berger, I., Hanif, M., Nazarov, A. A., Hartinger, C. G., John, R. O. Kuznetsov, M. L. et al. In Vitro Anticancer Activity and Biologically Relevant Metabolization of Organometallic Ruthenium Complexes with Carbohydrate-Based Ligands. Chemistry Europ. Journal 14, 9046-9057 (2008). 

Organometallic compounds often show unique catalytic properties that may also allow their use as potential drug candidates. The cyclopentadienyl-ruthenium carbonyl catalyst 75, that bears a quinoline-based bidentate ligand, was found to be a potent inhibitor of certain protein kinases <2006AGE1504>. 

Based in part on the article Ruthenium Organometallic Chemistry by Ulrich Koelle which appeared in the Encyclopedia of Inorganic Chemistry, First Edition. 

Two basic approaches have been taken. The first consists in grafting organometallic donor and acceptor groups, such as ferrocene [as in [84] (Calabrese et al, 1991)] ruthenium derivatives [as in [83] (Whittall et al, 1996)] and tungsten carbonyl, instead of their organic counterparts on tt-conjugated chains. Quite successful in this respect, although not truly org nometallic, are zwitterions based on borate donors and ammonium acceptors [86] (Lambert et ah, 1996) and Lewis acid complexation as in [85] (Kammler et al, 1996). 

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