2- cyclohexanol alkanal

Carbon atoms bonded to electron-withdrawing -OH groups are deshielded and absorb at a lower field in the 1,it NMR spectrum than do typical alkane carbons. Most alcohol carbon absorptions tall in the range 50 to 80 S, as the following data illustrate for cyclohexanol ... 

It is possible to perform the conversion CH2 C=0 on an alkane, with no functional groups at all, though the most success has been achieved with substrates in which all CH2 groups are equivalent, such as unsubstituted cycloalkanes. One method uses H2O2 and bis(picolinato)iron(II). With this method, cyclohexane was converted with 72% efficiency to give 95% cyelohexanone and 5% cyclohexanol. ... 

The selective oxidations of the terminal positions of -alkanes are an example of substrate-shape selectivity. Product-shape selectivity has been used to enhance the selectivity of the type IIaRH oxidation of cyclohexane [66-68], For example, oxidation of cyclohexane at 373 K for 8 hr using FeAlPO-31 (pore aperture 5.4 A) as a catalyst resulted in 2.5% conversion to a mixture which contained 55.3% of adipic acid and 37.3% of a mixture of cyclohexanol and cyclohexanone [68]. In contrast, oxidation under identical conditions using FeAlPO-5 (pore aperture 7.3 A) resulted in only 9.2% of adipic acid and 89.5%... 

Alkanes (e.g. adamantane, cyclohexane, toluene) were oxidised to alcohols and cyclohexanol to cyclohexanone by stoich. franx-Ba[Ru(OH)3(0)3]/AcOH, a reaction... 

K[Ru(0)(PDTA)].3Hj0 and Ru(0)(HEDTA) (PDTA=(propylenediaminetetra-acetate) -) are made by oxidation of K[Ru "Cl(PDTA.H)] or K[Ru" Cl(EDTA.H)] with PhIO electronic and ESR spectra were recorded. Rates and activation energies for epoxidation by stoich. Ru(0)(PDTA)] or Ru(0)(HEDTA)/water-dioxane of cyclo-alkanes were measured, as were those for oxidation of cyclohexane to cyclohexanol and cyclohexanone [632],... 

RuCl2(H20) ]+ This species was made from RUCI3 in HCl from pH 0.4-2.0. Kinetic studies suggest that in the epoxidation by [Ru(7l2(H20)4]X02/water-dioxane of cyclo-octene and -hexene homolytic cleavage of the 0-0 bond plays an essential part [771, 772], and that this is so for similar oxidation of alkanes (e.g. of cyclohexane to cyclohexanol) [771],... 

Most of the work reported with these complexes has been concerned with kinetic measurements and suggestions of possible mechanisms. The [Ru(HjO)(EDTA)] / aq. HjOj/ascorbate/dioxane system was used for the oxidation of cyclohexanol to cw-l,3-cyclohexanediol and regarded as a model for peroxidase systems kinetic data and rate laws were derived [773], Kinetic data were recorded for the following systems [Ru(Hj0)(EDTA)]702/aq. ascorbate/dioxane/30°C (an analogue of the Udenfriend system cyclohexanol oxidation) [731] [Ru(H20)(EDTA)]70j/water (alkanes and epoxidation of cyclic alkenes - [Ru (0)(EDTA)] may be involved) [774] [Ru(HjO)(EDTA)]702/water-dioxane (epoxidation of styrenes - a metallo-oxetane intermediate was postulated) [775] [Ru(HjO)(EDTA)]7aq. H O /dioxane (ascorbic acid to dehydroascorbic acid and of cyclohexanol to cyclohexanone)... 

The other alkanes were found to be much less reactive. Cyclohexane gave a cyclohexanol-one mixture, and adamantane was preferentially hydroxylated at the tertiary positions cis-decalin gave a mixture of cis- and frnns-9-decanol (together with 1- and 2-decalones), suggesting the transient formation of radical carbon intermediates, which were also revealed by trapping experiments with CC14. 

The porphyrin-iron(III)-peroxo complex [Fe(TPP)02] (163) was prepared by the reaction of K02 with Fen(TPP) in the presence of a crown ether, and characterized by spectroscopic methods [p(0—O) = 806 cm-1]542. This peroxo complex (163) was found to be inactive toward hydrocarbons. However, addition of excess acetic anhydride to (163) dissolved in a benzene-cyclohexane mixture results in the formation of cyclohexanol and cyclohexanone. This reaction is thought to proceed via acylation of the peroxo group, giving iron percarboxylate (164), which decomposes to an Fev-oxo compound (165) capable of hydroxylating alkanes.543 Such a mechanism has been suggested for the hydroxylation of camphor by Pseudomonas cytochrome P-450.544... 

The mechanism of oxidation of alkanes with dimethyldioxirane has been examined by measurement of the primary kinetic isotope effect for the oxidation of cyclohexane and methylcyclohexane in solution and in the gas phase. These experiments indicated that the major products (cyclohexanol and methylcyclohexanol) are probably formed via an electrophilic oxygen-insertion reaction while minor by-products may arise from radical reactions.90... 

Cyclohexane, the six-carbon ring hydrocarbon with the molecular formula C6H12, is the most significant of the cyclic alkanes. Under ambient conditions it is a clear, volatile, highly flammable liquid. It is manufactured by the hydrogenation of benzene and is used primarily as a raw material for the synthesis of cyclohexanol and cyclohexanone through a liquid-phase oxidation with air in the presence of a dissolved cobalt catalyst. 

Lead(IV)277 and silver(III)301 trifluoroacetates in TFA also oxidize alkanes at room temperature to give alkyl trifluoroacetates [see also Section III.D.3 for reactions of alkanes with Pd(II) trifluoroacetate]. The stoichiometric oxidation of cyclohexane to a mixture of cyclohexanol, cyclohexanone, and adipic acid by cobalt(III) perchlorate in aqueous acetonitrile has also been reported.240... 

An important goal is, therefore, to develop effective methods for catalytic oxidations with dioxygen, under mild conditions in the liquid phase. Two substrates which are often chosen as models for alkane oxidations are cyclohexane and adamantane. Cyclohexane is of immense industrial importance as its oxidation products - cyclohexanone and adipic acid - are the raw materials for the manufacture of nylon-6 and nylon-6,6. Adamantane is an interesting substrate as the ratio of oxidation at the secondary versus the tertiary C-H bonds is used as a measure of radical versus nonradical oxidation pathways. Industrial processes for the oxidation of cyclohexane, to a mixture of cyclohexanol and cyclohexanone, generally involve low conversions (under 10%). Even at such low conversions, selectivities are modest (70-80%) and substantial amounts of overoxidation products, mostly dicarboxylic acids, are formed. 

Organic substrates (alkanes alkenes, alcohols) are also photooxidized by trans-dioxo Ru and Os complexes [93]. The interest in these catalysts may lie in the transformation of cyclohexane to cyclohexanone and cyclohexanol in reasonable yields. The presence of alcohol, ester, and ketone functional groups is tolerated in the catalytic functionalization [94] with polyoxometallates and Pt as co-catalyst [95]. 

The controlled oxidation of alkanes into alcohols also attracts attention from an industrial point of view. Copper-based catalysts containing Tp ligands have been employed as catalysts for this reaction that led to a very interesting as well as unprecedented transformation with copper. Thus, when cyclohexane was reacted with in the presence of these catalysts, cyclohexane was partially converted into cyclohexanol and cyclohexanone, as expected. However, a certain amount of cyclohexane underwent dehydrogenation affording cyclohexene, in the first example of a copper-mediated alkane dehydrogenation process. Part of the cyclohexene was epoxidized in the reaction... 

Hydrogenation of olehns, aromatics, anilines, phenols, nitriles, naph> thalcnes. alcohols, and aldehydes. CO, and COj (Fischcr-Tropsch) Dehydrogenation of cyclohexanols. cyclohexanones, alkanes, alcohols Hydrogenolysts of C-C, C-N, N-O, steam reforming of CH4 Hydrogenation of olefins, aromatic aldehydes and ketones, aliphatic alcohols, aldehydes, ketones, unsaturatcd nitriles,... 

Dehydrogenation of cydohexanes, cyclohexenes, cyclohexanols, cyclohexanones, alkanes Deformylation of aldehydes Oxidation of hydrocarbons, CO. NHj Reduction of nitrogen oxides... 

Oxidation of cyclohexane with Oj can be described by a series of elementary reactions similar to the ones for n-butane. In this case, however, the hydrocarbon contains no primary hydrogens and three times as many secondary hydrogens as the acyclic alkane. Chain lengths are, therefore, longer and reaction products less numerous. Cyclohexyl hydroperoxide and cyclohexanol are the major propagation products while cyclohexanone and cyclohexanol are formed in termination ... 

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