Ruthenium hydrolysis

Ruthenium (III) chloride (2H2O) (P-form) [14898-67-0] M 207.4 + HjO, m >500 (dec), d 3.11, pK 3.40 (for aquo Rh hydrolysis). Dissolve in H2O, filter and concentrate to crystallise in the absence of air to avoid oxidation. Evaporate the solution in a stream of HCl gas while being heated just below it boiling point until a syrup is formed and finally to dryness at 80-100 and dried in a vacuum over H2SO4. When heated at 700° in the presence of CI2 the insoluble a-form is obtained [Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Vol II 1598 1965 J Org Chem 46 3936 1981]. 

The main use of acrolein is to produce acrylic acid and its esters. Acrolein is also an intermediate in the synthesis of pharmaceuticals and herhicides. It may also he used to produce glycerol hy reaction with isopropanol (discussed later in this chapter). 2-Hexanedial, which could he a precursor for adipic acid and hexamethylene-diamine, may he prepared from acrolein Tail to tail dimenization of acrolein using ruthenium catalyst produces trans-2-hexanedial. The trimer, trans-6-hydroxy-5-formyl-2,7-octadienal is coproduced. Acrolein, may also he a precursor for 1,3-propanediol. Hydrolysis of acrolein produces 3-hydroxypropionalde-hyde which could he hydrogenated to 1,3-propanediol. ... 

Hydroxy-5-oxo-3,5-seco-4-norandrostane-3-carboxylic acid has been prepared by ozonolysis of testosterone2-4 or of testosterone acetate, followed by alkaline hydrolysis,5 and by the oxidation of testosterone acetate with ruthenium tetroxide.9... 

Epimerization of 50 at C-3 furnished carba-a-DL-allopyranose (60). Stepwise, 0-isopropylidenation of 50 with 2,2-dimethoxypropane afforded compound 56. Ruthenium tetraoxide oxidation of 56 gave the 3-oxo derivative 57, and catalytic hydrogenation over Raney nickel converted 57 into the 3-epimer 58 exclusively. Hydrolysis of 58, and acetylation, provided the pentaacetate 59, which was converted into 60 on hydrolysis. ... 

In addition to the reactions discussed above, there are still other alkyne reactions carried out in aqueous media. Examples include the Pseudomonas cepacia lipase-catalyzed hydrolysis of propargylic acetate in an acetone-water solvent system,137 the ruthenium-catalyzed cycloisomerization-oxidation of propargyl alcohols in DMF-water,138 an intramolecular allylindination of terminal alkyne in THF-water,139 and alkyne polymerization catalyzed by late-transition metals.140... 

Partial hydrolysis of nitrile gives amides. Conventionally, such reactions occur under strongly basic or acidic conditions.42 A broad range of amides are accessed in excellent yields by hydration of the corresponding nitriles in water and in the presence of the supported ruthenium catalyst Ru(0H)x/A1203 (Eq. 9.19).43 The conversion of acrylonitrile into acrylamide has been achieved in a quantitative yield with better than 99% selectivity. The catalyst was reused without loss of catalytic activity and selectivity. This conversion has important industrial applications. 

When n = 0 or 1, the system appeared to be too rigid to allow the radical pair created upon hydrogen abstraction to form a carbon-carbon bond. Hence a considerable amount of chlorine appears in the product from radical abstraction from the solvent, carbon tetrachloride. When n = 2 the radicals are able to form a carbon-carbon bond. After a five-step workup of the crude irradiation product including reduction with LiAlH4, acetylation, dehydration, oxidation with ruthenium tetroxide, and hydrolysis a 16% yield of previously unreported 12-keto-3a-chlorestanol was obtained. However,... 

Fig. 2. Ligand substitution as a prodrug strategy for metallochem-otherapeutics (a) general scheme of prodrug activation by ligand substitution hydrolysis of a metal—halide bond is a typical activation pathway of metal-based anticancer drugs, as exemplified by the activation of cisplatin (b) and a ruthenium—arene complex (c).

Fig. 16. General reactivity of the ruthenium(II)-arenes. Hydrolysis of the Ru—Z bond gives the more reactive aqua species. The pKa of the coordinated water molecule is important, as the hydroxido complex is less reactive. The different structures are exemplified by the reactivity of [Ru(ri6-bip)Cl(en)]+ (10) for which Z = Cl.

The bifunctional amine-tethered ruthenium(II) arene complexes [Ru(r6 ti1-C6H5CH2(CH2)i1NH2)C12] (n = 1,2) (13a,b) show two consecutive hydrolysis steps to yield the mono- and bis-aqua complexes (64). At extracellular chloride concentrations, the majority of the complexes could be expected to be present as the mono-aqua adduct. Equilibrium constants were determined for both steps (for 13b, Ki = 145 mM K2 = 5.4 mM) and found to be considerably higher than those of cisplatin, which also has two reactive sites available. 

Fig. 24. Comparison between the osmium- and ruthenium-arenes, exemplified by the respective [M(ri6-bip)Cl(en)]+ complexes. Although the crystal structures show the complexes to be isostructural with similar M-Cl bond lengths (a), the properties of the complexes are quite different, illustrated by the differences in hydrolysis rate h1/2), pAa, and 5 -GMP binding (the black box denotes the amount of OP03-bound 5 -GMP) (b).

The use of an extended arene (tetrahydroanthracene) in [OsCl(en)(ri6-tha)]+ (29) gave rise to a similar potency (112). This is in contrast with the data for ruthenium-arenes, where the same substitution gave rise to a 10-fold increase in activity. Further work therefore needs to determine if the extended Os-arenes can intercalate into DNA in a manner similar to Ru-arenes. Replacement of the iV /V-chelating ligand en for other AyV-bidentates with pyridine, aliphatic amine, or azopyridine donor atoms leads to loss of activity, probably because of slower hydrolysis and higher acidity of the coordinated water (112). 

Subsequent insertion of CO into the newly formed alkyl-ruthenium moiety, C, to form Ru-acyl, D, is in agreement with our 13C tracer studies (e.g., Table III, eq. 3), while reductive elimination of propionyl iodide from D, accompanied by immediate hydrolysis of the acyl iodide (3,14) to propionic acid product, would complete the catalytic cycle and regenerate the original ruthenium carbonyl complex. 

Sweigart, D.A., Trialkyl phosphite addition to the bis(benzene)-iron(II) and -ruthenium(II) dications catalyzed hydrolysis to dialkyl phosphites,. Chem. Soc., Chem. Commun., 1159, 1980. 

The ruthenium-based reaction conditions were, however, demonstrated to be acidic in acetone. Tandem acetal hydrolysis was observed in the cycloisomerization of 56 (Equation (36)) and unexpected 1,5-diene 59 arose from the... 

There are several examples of one-pot reactions with bifunctional catalysts. Thus, using a bifunctional Ru/HY catalyst, water solutions of corn starch (25 wt.%) have been hydrolyzed on acidic sites of the Y-type zeolite, and glucose formed transiently was hydrogenated on ruthenium to a mixture of sorbitol (96%), mannitol (1%), and xylitol (2%) [68]. Similarly a one-pot process for the hydrolysis and hydrogenation of inulin to sorbitol and mannitol has been achieved with Ru/C catalysts where the carbon support was preoxidized to generate acidic sites [69]. Ribeiro and Schuchardt [70] have succeeded in converting fructose into furan-2,5-dicarboxylic acid with 99% selectivity at 72% conversion in a one-pot reaction... 

Hydrolysis of the ester forms adipic acid, used to manufacture nylon—6. Carbonylations of nitroaromatics are used to synthesize an array of products including amines, carbamates, isocyanates, ureas and azo compounds. These reactions are catalyzed by iron, ruthenium, rhodium and palladium complexes. For example, carhonylation of nitrobenzene in the presence of methanol produces a carbamate ... 

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