Alkanes to ketones

Ru(acac)(bpy)3](PFg) is made from RuCl Cbpy), acetylacetone and (NH )PFg. It is dark brown IR and electronic spectra, TGA and cyclic voltammetry were measured. As [Ru(acac)(bpy)2]" /TBHP/CH3Cl2 it oxidised primary alcohols to aldehydes, secondary alcohols to ketones, di-tert-butylcatechol to the o-benzoqui-none and alkanes to ketones, e. g. ethylbenzene was converted to acetophenone and fluorene to fluorenone [787],... 

The selective oxidation of alkanes to ketones using Fe(III)(PA)3 and Fe(III)(PA)2Cl2, Pyr2H (PA = picolinic acid), is performed with BTSP and proceeds by a nonradical mechanism. The Fe -Fe manifold is responsible for the oxidation process (equations 55 and 56). ... 

Use of the urea-hydrogen peroxide complex and /V,/V -bis(TMS) urea provides an improved method126 for the preparation of bis(TMS) peroxide, TMSOOTMS. In the presence of Fe(m)(picolinic acid)3, bis(TMS) peroxide carries out selective oxidation of alkanes to ketones by a non-radical mechanism. The Fe(III)-Fe(IV) manifold is believed to be responsible127. On the other hand, using FeCU in pyridine, alkyl chlorides are formed through a radical mechanism. Here, the Fe(n)-Fe(IV) manifold has been proposed128. 

Mc.Murrey and co-workers modified the reaction by carrying it out in a reductive medium of TiCla followed by hydrolysis and an oxidizing medium of O3 (92a] and (92b] respectively. Sec also Bartlett et al. (93 ]. They used r-butyl hydroperoxide in the presence of peniavalent vanadium salt as a catalyst, Korn-blum and Wade (94a] gave an unusual method of oxidation of secondary nitro-alkanes to ketones with nitrous esters and sodium nitrite at room temperature ... 

Figure 5. "Dioxygenase-like" mechanism for the oxidation of alkanes to ketones by O2 catalyzed by photoactivated Fe(TOCPP)OH.

The Gattermann-Koch reaction when appHed to alkenes or alkanes gives ketones or acids but not aldehydes. However, the Vilsmeier aldehyde synthesis can be appHed to aUphatic compounds. For example, 1,2-diaLkoxyethylenes react with /V-methy1foTmani1ide and POCl to give alkoxymalondialdehydes ... 

In general, peroxomonosulfates have fewer uses in organic chemistry than peroxodisulfates. However, the triple salt is used for oxidizing ketones (qv) to dioxiranes (7) (71,72), which in turn are useful oxidants in organic chemistry. Acetone in water is oxidized by triple salt to dimethyldioxirane, which in turn oxidizes alkenes to epoxides, polycycHc aromatic hydrocarbons to oxides and diones, amines to nitro compounds, sulfides to sulfoxides, phosphines to phosphine oxides, and alkanes to alcohols or carbonyl compounds. 

Ozone can be used to completely oxidize low concentrations of organics in aqueous streams or partially degrade compounds that are refractory or difficult to treat by other methods. Compounds that can be treated with ozone include alkanes, alcohols, ketones, aldehydes, phenols, benzene and its derivatives, and cyanide. Ozone readHy oxidizes cyanide to cyanate, however, further oxidation of the cyanate by ozone proceeds rather slowly and may require other oxidation treatment like alkaline chlorination to complete the degradation process. 

TS-1 is a material that perfectly fits the definition of single-site catalyst discussed in the previous Section. It is an active and selective catalyst in a number of low-temperature oxidation reactions with aqueous H2O2 as the oxidant. Such reactions include phenol hydroxylation [9,17], olefin epoxida-tion [9,10,14,17,40], alkane oxidation [11,17,20], oxidation of ammonia to hydroxylamine [14,17,18], cyclohexanone ammoximation [8,17,18,41], conversion of secondary amines to dialkylhydroxylamines [8,17], and conversion of secondary alcohols to ketones [9,17], (see Fig. 1). Few oxidation reactions with ozone and oxygen as oxidants have been investigated. 

One of the exciting results to come out of heterogeneous catalysis research since the early 1980s is the discovery and development of catalysts that employ hydrogen peroxide to selectively oxidize organic compounds at low temperatures in the liquid phase. These catalysts are based on titanium, and the important discovery was a way to isolate titanium in framework locations of the inner cavities of zeolites (molecular sieves). Thus, mild oxidations may be run in water or water-soluble solvents. Practicing organic chemists now have a way to catalytically oxidize benzene to phenols alkanes to alcohols and ketones primary alcohols to aldehydes, acids, esters, and acetals secondary alcohols to ketones primary amines to oximes secondary amines to hydroxyl-amines and tertiary amines to amine oxides. 

By 1990, most of the catalytic reactions of TS-1 had been discovered. The wide scope of these reactions is shown in Fig. 6.1.35 Conversions include olefins and diolefins to epoxides,6,7 12 16 19 21 24 34 36 38 13 aromatic compounds to phenols,7,9 19 25 27 36 ketones to oximes,11 20 34 46 primary alcohols to aldehydes and then to acids, secondary alcohols to ketones,34-36 42 47-30 and alkanes to secondary and tertiary alcohols and ketones.6 34 43 31 52... 

The formation of lipid components in an aqueous phase at temperatures from 370 to 620 K was studied by Rushdie and Simoneit (2001), who heated aqueous solutions of oxalic acid in a steel vessel for 2 days the yield of oxidized compounds reached a maximum (5.5% based on oxalic acid) between 420 and 520 K. A broad spectrum of compounds was obtained, from n-alkanes to the corresponding alcohols, aldehydes and ketones. At higher temperatures, i.e., above 520-570 K, cracking reactions competed with the synthetic reactions. 

The alkane series is present in mass spectra of any compound containing an alkyl group. In case of isobaric series (e.g., alkanes and ketones) one should pay attention to the intensities of the isotopic peaks. Thus, for the isobaric ions of m/z 43 (CH3CO and C3H7) the abundance of the isotopic peak (m/z 44 ion) will be 2.2% and 3.3%, respectively. The situation is very simple with A + 2 elements. In this case there are two homologous ion series due to A and A + 2 ions. It is worth emphasizing that... 

The reagents RuCl3/Na(Br03) /aq. M Naj(C03) and RuCl3/K3(S30j)/aq. M KOH oxidised activated primary alkyl halides RX to carboxylic acids and secondary alkyl halides to ketones, e.g. 1-bromophenylethane to acetophenone [213]. Stoicheiometrically fran -Ba[Ru(OH)2(0)3]/CF3COOH/(bpy)/CH3Cl3 oxidised alkanes (e.g. cyclohexane, adamantane, n-hexane, ethane) to ketones or acids, perhaps via Ru (0) (bpy)(CF C(O)O) [550]. 

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