Ruthenium benzene

Iron and Ruthenium.- Benzene reacts with Fe vapour to give a mlx-ture of products Including the 18-electron complex (ti-PhH)Fe(n -CgHg) and the 20-electron complex (n-PhH)2Fe. The extensive chemistry of (hmb)2Fe has been explored with particular reference... 

Figure 7.2. Structure of dpp-bridged ruthenium benzene complex.

Pyrido[],2-a]pyrimidine-3,7-dicarboxylate 396 was also obtained in the reaction of diazo compound 395 and methyl vinyl ketone in boiling benzene in the presence of a catalytic amount of ruthenium acetate. 

Asymmetric epoxidation of olefins with ruthenium catalysts based either on chiral porphyrins or on pyridine-2,6-bisoxazoline (pybox) ligands has been reported (Scheme 6.21). Berkessel et al. reported that catalysts 27 and 28 were efficient catalysts for the enantioselective epoxidation of aryl-substituted olefins (Table 6.10) [139]. Enantioselectivities of up to 83% were obtained in the epoxidation of 1,2-dihydronaphthalene with catalyst 28 and 2,6-DCPNO. Simple olefins such as oct-l-ene reacted poorly and gave epoxides with low enantioselectivity. The use of pybox ligands in ruthenium-catalyzed asymmetric epoxidations was first reported by Nishiyama et al., who used catalyst 30 in combination with iodosyl benzene, bisacetoxyiodo benzene [PhI(OAc)2], or TBHP for the oxidation of trons-stilbene [140], In their best result, with PhI(OAc)2 as oxidant, they obtained trons-stilbene oxide in 80% yield and with 63% ee. More recently, Beller and coworkers have reexamined this catalytic system, finding that asymmetric epoxidations could be perfonned with ruthenium catalysts 29 and 30 and 30% aqueous hydrogen peroxide (Table 6.11) [141]. Development of the pybox ligand provided ruthenium complex 31, which turned out to be the most efficient catalyst for asymmetric... 

Novel ruthenium-amidinate complexes of the type (j -CgHsRlRufamidina-te)X (R = Me, OMe, F X = Cl, Br, OTf) and [Ru(amidinate)(MeCN)4][PF6] have been synthesized by photochemical displacement of the benzene ligand in (j -CgHglRufamidinatelX by substituted arenes or MeCN. The acetonitrile ligands of [Ru(amidinate)(MeCN)4][PF6] are easily replaceable by other cr-donor ligands (L) such as pyridines, phosphines, and isocyanides to afford the corresponding derivatives [Ru(amidinate)(MeCN) (L)4 ][PF6] n — 1, 2). These reactions are summarized in Scheme 142. ... 

The bulky ruthenium TMP complex Ru(TMP) is very electron deficient in the absence of any coordinating ligand, and a tt-complex with benzene has been proposed. In fact, it readily coordinates dinitrogen, forming the mono- and bis-N adducts Ru(TMP)(N2)(THF) and Ru(TMP)(N2)2, - As a result, the use of the TMP ligand for careful stereochemical control of the chemistry at the metal center, which has been very successful for the isolation of elusive rhodium porphyrin complexes, is less useful for ruthenium (and osmium) because of the requirement to exclude all potential ligands, including even N2,... 

The most recent report of -coordination to a ruthenium porphyrin fragment details the reaction of [Ru(OEP)j2 with C o in benzene/THF (100 1) solution. The UV-visible spectrum of the complex showed a new band at 780 nm, not observed in the spectrum of either Ru(OEP) 2 or C(,o, and H and C NMR data also indicated the presence of a new complex. This has been formulated on the basis of the spectroscopic data as the fullerene complex Ru(OEP)(... 

Dibenzenechromium was studied by Baumgartner et al. 15). They found that the yield of Cr(Ph)2 was 11.8%. [One cannot fail to be struck by the similarity in yields of FeCp2, RuCp2, and Cr(PhH)2, although it may well be merely coincidence.] On heating the irradiated samples to 110°C, they found the yield to increase to 19.4%. It was found that dissolution of the radioactive crystals in benzene yielded no further Cr(PhH)2. This stands in contrast to the above-mentioned results of Zahn and Harbottle which, though not strictly comparable, show Cp to be quite reactive toward ruthenium atoms. Dibenzenechromium was also formed in low yield 14) from neutron irradiation of PhHCr(CO)3, as will be discussed in more detail later. 

In fact, partial hydrogenations are rarely described with soluble nanoparticle catalysts. Two examples are explained in the Uterature, one reported by Finke and coworkers in the hydrogenation of anisole with polyoxoanion-stabihzed Rh(0) nanoclusters [26] and one reported by Dupont and coworkers in the hydrogenation of benzene with nanoscale ruthenium catalysts in room temperature imidazoUiun ionic Uquids [69]. hi these two cases, the yields are very modest. 

MandyPhos Initial attempts to synthesize defined chelating biphosphine complexes by reacting (1) with established Ruthenium(II) precursors such as [Ru(COD)Cl2]x, [Ru(benzene)Cl2]2, [Ru(p-cymene)Cl2]2, (COD)Ru(Methylallyl)2,... 

PUSRIE PUSRUQ REBZON ROHXAN 1,4,7,10,13,16-Hexathiacyclooctadecane iodine 1,4,7,10,13,16,19,22-Octathiacyclotetracosane iodine l,2,4,5-Tetrakis(isopropylthio)benzene tris(diiodine) cis-Bis(N,N-diethyldithiocarbamato)-dicarbonyl-ruthenium(II) iodine... 

It has also been shown that dimethylsilyl enolates can be activated by diisopropylamine and water and exhibit a high reactivity toward iV-tosyl imines to give Mannich-type reaction products in the absence of a Fewis acid or a Bronsted acid.51 For example, the reaction of [(1-cyclohexen-l-yl)oxy]dimethylsilane with 4-methyl-A -(phenylmethylene)benzene sulfonamide gave re/-4-methyl-N- (f )-[(15)-(2-oxocyclohexyl)phenyl-methyl] benzenesulfonamide (anti-isomer) in 91% yield stereoselectively (99 1 anti syn) (Eq. 11.30). On the other hand, Fi and co-workers reported a ruthenium-catalyzed tandem olefin migration/aldol and Mannich-type reactions by reacting allyl alcohol and imine in protic solvents.52... 

Benzeneruthenium(ll) chloride dimer Ruthenium, bis(ri6-benzene)di-p-chlorodichlorodi- (9) (37366-09-9)... 

Quinoxalines 85 have been prepared by the reaction of diols with benzene-1,2-diamines in the presence of a ruthenium catalyst <06TL5633>. Iodobenzene diacetate has been suggested as a less toxic alternative to lead tetraacetate for the oxidative cyclisation of iminooximes to quinoxaline iV-oxides 86 <06TL4969>. 

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