2- butanol, oxidation rate

The extent of coupling is also influenced by the solvent. In the hydrogenation of aniline over ruthenium oxide, coupling decreased with solvent in the order methanol > ethanol > isopropanol > t-butanol. The rate was also lower in the lower alcohols, probably owing to the inhibiting effect of greater concentrations of ammonia (44). Carboxylic acid solvents increase the amount of coupling (42). 

Alcohol oxidation over the loose powder catalysts were conducted in a fixed bed reactor at 230 °C and atmospheric pressure. The details of the reactor system was previously described elsewhere [8]. The catalysts were pretreated in a flow of Oj/He for 15 min prior to oxidation reaction. A reactant stream of CHjOH/Oj/He = 6/13/81 with a total flow rate of 100 ml/min was used for methanol oxidation. For ethanol and 2-butanol oxidation, a gaseous mixture of Oj/He (13/81 ml/min) containing saturated ethanol or 2-butanol vapor at ambient temperature was introduced into the reactor. Analyses of reactants and products were carried out by an on-line Hewlett Packard 5890B GC. The spent catalysts were also characterized by Raman spectrometer. 

Alkali metal benzhydrolate oxidizes in toluene [111] and benzene [112] as well as in f-butanol [113] with autocatalysis that is produced by the K02 formed in the oxidation [113]. The induction period disappears when K02 is added to a solution of potassium benzhydrolate. The kinetics of oxidation of sodium benzhydrolate was studied by Pereshein et al. [111]. The maximum oxidation rate appears to be approximately proportional to [RONa] [02]/[ROH],the activation energy being 12 kcal mole-1. The inhibiting action of alcohol (benzhydrol and t-butanol) on the oxidation of metal benzhydrolates was noted by Russell et al. [110], No deuterium exchange was observed during the oxidation of potassium benzhydrolate in t-butanol. Thus no dianions are produced from benzhydrolate ion by the equilibrium reaction... 

For the pyridine-free systems, the best efficiency (15%) was obtained in acetone but the principal product was cyclohexanol. For the GoChAgg system, Geletii et al described good results obtained in acetonitrile/pyridine 2 1, but assured that pyridine was essential and must be present in the system. On the other hand, in a very recent publication Barton etal reported that pyridine can be completely replaced by ferf-butanol with only a small reduction of the total hydrocarbon activation and a slightly reduced onerol ratio. However, the initial oxidation rate was pH dependent and buffering of the system was necessary. 

The general reactivity of oxidized Ni anodes in various f-butanol/H20 mixtures was followed by cyclic voltammetry. " The coulombic and organic product yields of aldehyde and acid were determined for various primary alcohol derivatives. Substituent effect on the anodic oxidation rates of a series of benzyl alcohols were evaluated. Attempts were made to relate the oxidation rates to the Hammett cr parameter for substituent properties. 

MeOC6H4)2CHOH. Addition of H2O increases the turnover numbers by factors of 2-6, depending on the substtate, while addition of aq. KOH or NaOH inaeases turnovers by a further factor of up to 6. Thus addition of KOH increases turnovers for isopropanol and benzyMcohol by factors of 5-6. Maximum turnovers over 24 h of -200 (100% yield) were achieved for 2-, 3-, or 4-MeO substituted benzyl alcohols, and the catalyst stiU remains active. Oxidation of primary alcohols (such as 1-butanol) to the aldehyde was less efficient, with turnovers of up to 40 being noted over 24 h, with no formation of carboxylic acids. The use of O2 rather than air did not increase the oxidation rates ... 

The second major discovery regarding the use of MTO as an epoxidation catalyst came in 1996, when Sharpless and coworkers reported on the use of substoichio-metric amounts of pyridine as a co-catalyst in the system [103]. A change of solvent from tert-butanol to dichloromethane and the introduction of 12 mol% of pyridine even allowed the synthesis of very sensitive epoxides with aqueous hydrogen peroxide as the terminal oxidant. A significant rate acceleration was also observed for the epoxidation reaction performed in the presence of pyridine. This discovery was the first example of an efficient MTO-based system for epoxidation under neutral to basic conditions. Under these conditions the detrimental acid-induced decomposition of the epoxide is effectively avoided. With this novel system, a variety of... 

The cobaltous acetate reduction of tert-butyl hydroperoxide in acetic acid yields mainly ter/-butanol and oxygen the metal ion stays in the +2 oxidation state because of the reactivity of Co(III) towards hydroperoxides (p. 378) °. The rate law is... 

However, copper alkoxides with longer chains appear to be more soluble in their parent alcohol. S. Shibata et al. (20) have used the n-butoxides of Y, Ba and Cu dissolved in n-butanol and hydrolyzed with water. They obtain a precipitate of oxides that is composed of a very fine submicron powder that readily sinters starting above 250°C. However, the different reaction rates for the hydrolysis and the precipitation of the three different cations lead to cationic segregation. 

Cumene does not undergo oxidation at a measurable rate. 1-Butylbenzene undergoes oxidation mainly in the side chain, with traces of aromatic ring oxidation, producing 1-phenyl-1-butanol, l-phenyI-3-butanol, and the corresponding ketones (Clerici, 1991). 

The sulfate anion radical is not a very strong hydrogen acceptor. It acquires an atomic hydrogen from organic substrates at significantly smaller rates a compared with the rates for one-electron oxidations. For instance, dehydration rate constants are 107, 106 and 105 I.-mole -sec 1 for methanol, tert-butanol, and acetic acid, respectively (Goldstein Mc-Nelis 1984 Zapol skikh et al. 2001). Such a peculiarity is very important for the selectivity of ion radical syntheses with the participation of SOT. 

Primary alcohols are oxidized to aldehydes, n-butanol being the substrate oxidized at the highest rate. Although secondary alcohols are oxidized to ketones, the rate is less than for primary alcohols, and tertiary alcohols are not readily oxidized. Alcohol dehydrogenase is inhibited by a number of heterocyclic compounds such as pyrazole, imidazole, and their derivatives. 

Direct photolysis of aqueous solutions of the 2-chloro-.v-iriaz.ine herbicides (atrazine, simazine, propazine) proceeds via excitation of the triazine molecule, followed mainly by dechlorination and hydroxylation to form the corresponding hydroxytriazine (Pape and Zabik, 1970 Khan and Schnitzer, 1978 Chan et al, 1992 Lai et al, 1995 Schmitt et al, 1995 Sanlaville et al, 1997 Torrents et al, 1997 Texier et al, 1999b Hequet et al, 2001). This observation - plus the fact that when 2-chloro-v-triazine herbicides are photolyzed in methanol, ethanol, and n-butanol, the respective 2-alkoxy derivatives are formed - indicates a mechanism involving photochemical solvolysis rather than the involvement of hydroxyl radicals. This conclusion is supported by the fact that the rate of oxidation of atrazine was unaffected by the presence of either bicarbonate ion (Beltran et al, 1993) or ferf-butanol (Torrents et al, 1997), both strong hydroxyl radical scavengers. 

A method apparently fundamentally related to the above is illustrated by the fractional catalytic dehydration of di-2-butanol observed by Schwab and Rudolph.91 The alcohol recovered after partial thermal dehydration upon a film of copper supported on powdered d- or 1-quartz was faintly active in the same sense as the quartz. Similar results were noted after partial catalytic oxidation on the same surfaces. These results have not been explained fully it is possible that each of the two active forms of the alcohol is adsorbed momentarily on the quartz-copper interface the two diastereoisomeric combinations thus formed then react at different rates. The method is not practical in its present form. 

Lewis acid and the oxygen atom of the phosphane oxide, respectively. With this catalyst system, N-allyl- and N-benzhydrylimines generally gave lower enantioselectivities. The addition of phenol was found to have a beneficial effect on the reaction rates. The JandaJEL -supported bifunctional catalyst of 14 has also been shown by Shibasaki and co-workers to promote the Strecker-type reaction of aromatic and a,/ -unsaturated imines in excellent yields with 83-87% ee in the presence of tert-butanol (110%) [11]. The reactivity of the Janda/EL catalyst was comparable to the homogeneous analogue 14, and the catalyst could be recycled at least four times. 

Recently, evidence for this scheme was presented in that the tert-butanol radical was observed by flow-ESR a rate constant of 2x 106M-1 s 1 for Reaction (15) has been proposed [116], It seems likely now that terf-butanol cannot be used to distinguish between the hydroxyl radical and higher oxidation states. 

A final oxidation type that has been observed is the catalysis of Baeyer-Villiger-type oxidations of cyclic ketones to lactones.53 Understandably, the strained cyclobutanone is the best substrate, giving 80% conversion after 24 h at 25°C (tert-butanol solvent). Larger ring ketones proceed more slowly, although selectivity remains high. Elevated temperatures increase the rate without sacrificing selectivity cyclopentanone is converted to the lactone in 72% yield after 1 h at 70°C in THF. Complex 4 was presumed to be the active species. 

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