Ruthenium catalysis arenes

The addition of carbonyl-functionalized arenes to electron-rich alkenes and alkenes is achieved under ruthenium catalysis (Murai reaction) S. Murai, F. Kakiuchi, S. Sekine, Y. Tanaka, A. Kamatani, M. Sonoda, N. Chatani, Nature 1993, 366, 529-531. 

Yan YK, Melchart M, Habtemariam A, Peacock AFA, Sadler PJ (2006) Catalysis of regioselective reduction of NAD+ by ruthenium(II) arene complexes under biologically relevant conditions. J Biol Inorg Chem 11 483—488... 

Reactions of arenes carrying a coordinating substituent with alkenes may give alkylated derivatives when catalysed by ruthenium biscarboxylate complexes. Experiments with deuterium-labelled compounds indicate that carbon-hydrogen metallation is reversible, so that reductive elimination from intermediates such as (90) is rate determining. Carboxylate-assisted ruthenium catalysis also allows the reaction of 2-arylpyridines with methylenecyclopropane to give derivatives, (91), in which the cyclopropane ring is conserved. ... 

It is clear from the preceding section that the field of tethered arene-metal complexes is dominated by ruthenium and by arene-phosphines as ligands. In part, this situation has arisen because of the current surge of interest in the catalytic properties of ruthenium complexes in organic synthesis.85,86 Moreover, the tethered arene complexes are usually air-stable, crystalline solids with a well-defined, half-sandwich molecular geometry that, in principle, can lock the configuration at the metal centre. These compounds should, therefore, be ideal both for the study of the stereospecificity of reactions at the metal centre and for stereospecific catalysis. 

Heterometal alkoxide precursors, for ceramics, 12, 60-61 Heterometal chalcogenides, synthesis, 12, 62 Heterometal cubanes, as metal-organic precursor, 12, 39 Heterometallic alkenes, with platinum, 8, 639 Heterometallic alkynes, with platinum, models, 8, 650 Heterometallic clusters as heterogeneous catalyst precursors, 12, 767 in homogeneous catalysis, 12, 761 with Ni—M and Ni-C cr-bonded complexes, 8, 115 Heterometallic complexes with arene chromium carbonyls, 5, 259 bridged chromium isonitriles, 5, 274 with cyclopentadienyl hydride niobium moieties, 5, 72 with ruthenium—osmium, overview, 6, 1045—1116 with tungsten carbonyls, 5, 702 Heterometallic dimers, palladium complexes, 8, 210 Heterometallic iron-containing compounds cluster compounds, 6, 331 dinuclear compounds, 6, 319 overview, 6, 319-352... 

In the first part of this article, focusing attention on polymer-supported cobalt phosphine complex 1 and arene ruthenium complex 2, we review contributions from our laboratory that show how organometallics can be efficiently attached to derivitised polystyrene and we outline their synthetic versatility.2,3 Following this, we discuss the preparation of a supported ruthenium complex, 3, and its use in oxidation and transfer hydrogenation catalysis. 

Perfluoroalkylation. Arenes and heteroarenes give perfluoroalkyl derivatives upon reaction with RfS02CI under ruthenium complex catalysis. Pyrroles also undergo this reaction. ... 

Enol formates, which are formylating agents under neutral conditions, are obtained from 1-alkynes and formic acid by arene-ruthenium(II) catalysis Heating acetylenes (phenylacetylene, diphenylacetylene, 1-octyne or 4-octyne) with formic acid to 100°C produces ketones and carbon monoxide. It was shown by NMR spectroscopy that the process involves the intermediate formation of enol formates (equation 35). Treatment of terminal alkynes with carbon dioxide and secondary amines in the presence of a ruthenium catalyst affords vinyl carbamates, e.g. equation 36 d88. reviews, see References 189 and 190. 

In addition to transfer hydrogenation reactions, arene ruthenium complexes also display excellent activity in the catalytic hydrogenation of olefins and alkynes including asymmetric reduction [40]. Remarkably, this process occurs under milder conditions, than required for catalysis with the dissociation of arene-metal bond. Lately, arene iridium complexes have also been found to be effective hydrogenation catalysts [41 ]. It is noteworthy that iridium can also promotes addition to the carbon-nitrogen double bond. 

Since the researcher normally looks to the chemistry of soluble complexes in designing polymer-bound catalysts, it is notable that some areas that have proven fruitful in homogeneous catalysis have been omitted from investigations using polymer-bound catalysts. One of these areas concerns the reactions of arenes. Benzene, for example, may be hydrogenated with homogeneous cobalt phosphite and ruthenium phosphine complexes, but the corresponding supported versions are not reported. Aryl halides may be carboxylated in the presence of a soluble palladium catalyst ... 

Rossi, L. M. Machado, G. (2009). Ruthenium nanoparticles prepared from ruthenium dioxide precursor Highly active catalyst for hydrogenation of arenes under mild conditions. Journal of Molecular Catalysis A Chemical, Vol.298, No.1-2, (February 2009), pp. 69-73, ISSN 1381-1169... 

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