Cyclopentadienyl ruthenium

Reaction of ruthenium cyclopentadienyl bisacetonitrile carbene (22) with electron-poor acetylenes yields the allylcarbene (23).28 As evidenced from DFT calculations, the reaction is likely to proceed by NHC insertion into the ruthenium-carbene bond in the metallacyclopentatriene (24). An unexpected reaction of NHC in the coordination sphere of a metal has been disclosed.29 In this example, NHC is not coordinating the metal but is linked to a phosphorus atom with a shift of the carbene centre as shown in (25). 

There is a pronounced tendency for ruthenium cyclopentadienyl complexes with attached phosphorus ligands to undergo a wide variety of intramolecular metallation reactions. Heating (T75-C5H5)(PPh3)2RuMe in decalin for 24 hours leads to the orthometallated complex 135 in reasonable yield [Eq. (Ill)] (6,103). The mechanism presumably involves initial loss of... 

Among the products of interaction of the ruthenium cyclopentadienyl complexes with alkynes, ruthenacycopenta-dienes and ruthenacyclopentatrienes occur quite often <1991JCD1589, 1997M1189, 1998CRV2599, 1998CRV2797,... 

Schdllkopfs chiral glycine enolate equivalents, as in the elegant synthesis of the central diarylether unit of ristocetin [169]. It is remarkable that these limitations were partly lifted by using, instead of the manganese tricarbonyl complex the corresponding iron or ruthenium cyclopentadienyl complexes [170] (Scheme 62). 

In 2005, ruthenium cyclopentadienyl complexes were found to catalyze the formation ofthe complementary 1,5-disubstituted triazole from azides and terminal... 

The vinylidene/acetyhdo interconversions carried out in this experiment are similar to those seen for other metal complexes" and are relevant to the known ability of (q -C5H5)RuCl(PPh3)2 to catalyze the dimerization of phenylacetylene to a mixture of Z- and -l,4-diphenyl-l-buten-3-yne. The chemistry of ruthenium cyclopentadienyl complexes has been reviewed. ... 

A review covering the literature published up to 2001 on the synthesis and reactivity of ruthenium cyclopentadienyl-arene complexes is available. 

Akbayeva DN, Gonsalvi L, Oberhauser W, Peruzzini M, Vizza F, Briiggeller P, Romerosa A, Sava G, Bergamo A (2003) Synthesis, catalytic properties and biological activity of new water soluble ruthenium cyclopentadienyl PTA complexes [(C5R5)Ru(PTA)2Cl] (R = H, Me PTA = l,3,5-triaza-7-phosphaadamantane). Chem Common 264-265... 

Bolano S, Gonsalvi F, Zanobini F, Vizza F, Bertolasi V, Romerosa A, Peruzzini M (2004) Water soluble ruthenium cyclopentadienyl and aminocyclopentadienyl PTA complexes as catalysts for selective hydrogenation of a, -unsaturated olefins. (PTA = l,3,5-triaza-7-phosphaadamantane). J Mol Catal A Chem 224 61-70... 

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