Olefins co-oxidation

I. Synthesis of Endoperoxides via Thiol Olefin Co-oxidation Methodology... 

Further, the thio-olefin co-oxidation (TOCO) radical chain reaction (cf Chapter 9.11.9.3.3) using ground state molecular oxygen was employed to synthesize a series of benzo-fused cyclic peroxy ketals 232 in good yield (Scheme 64) <2006T4120>. 

In the presence of reactive olefins, co-oxidation of the thiol with the olefin [94,95,106] increases the rate of disappearance of the thiol by the sequence... 

Olefin-CO coploymers Olefin p-complexes Olefin Fibers Olefin hydroformylation Olefin hydrogenation Olefimc alcohols Olefin isomerization Olefin metathesis Olefin oligomers Olefin oxides... 

Peracids react heterolytically with olefins with the formation of epoxides by the Prilezhaev reaction. So, the co-oxidation of aldehydes with olefins has technological importance. Peracids react with ketones with formation of lactones. These reactions will be discussed in Section 8.2. The oxidation of aldehydes are discussed in monographs [4-8]. 

Aldehydes do not co-oxidize alkanes due to a huge difference in the reactivity of these two classes of organic compounds. Alkanes are almost inert to oxidation at room temperature and can be treated as inert solvents toward oxidized aldehydes [35]. Olefins and alkylaromatic hydrocarbons are co-oxidized with aldehydes. The addition of alkylaromatic hydrocarbon (R2H) to benzaldehyde (R1H) retards the rate of the initiated oxidation [36-39]. The rate of co-oxidation obeys the equation [37] ... 

Both these reactions occur rapidly. The kinetics and the products of co-oxidation of aldehydes and olefins were studied by Emanuel and coworkers [47-49], The values of the rate constants of the addition of acylperoxyl radical to olefins are presented in Table 8.8. The experimental data on aldehyde co-oxidation are discussed in monographs [4-6]. 

The electrochemical Wacker-type oxidation of terminal olefins (111) by using palladium chloride or palladium acetate in the presence of a suitable oxidant leading to 2-alkanones (112) has been intensively studied. As recyclable double-mediatory systems (Scheme 43), quinone, ferric chloride, copper acetate, and triphenylamine have been used as co-oxidizing agents for regeneration of the Pd(II) catalyst [151]. The palladium-catalyzed anodic oxidation of... 

The use of CO as a chemical probe of the nature of the molecular interactions with the surface sites of metallic catalysts [6] was the first clear experimental example of the transposition to surface science and in particular to chemisorption of the concepts of coordination chemistry [1, 2, 5], In fact the Chatt-Duncanson model [7] of coordination of CO, olefins, etc. to transition metals appeared to be valid also for the interactions of such probes on metal surfaces. It could not fit with the physical approach to the surface states based on solid state band gap theory [8], which was popular at the end of 1950, but at least it was a simple model for the evidence of a localized process of chemical adsorption of molecules such as olefins, CO, H, olefins, dienes, aromatics, and so on to single metal atoms on the surfaces of metals or metal oxides [5]. 

Allylic acetoxylation with palladium(II) salts is well known however, no selective and catalytic conditions have been described for the transformation of an unsubstituted olefin. In the present system use is made of the ability of palladium acetate to give allylic functionalization (most probably via a palladium-x-allyl complex) and to be easily regenerated by a co-oxidant (the combination of benzoquinone-manganese dioxide). In contrast... 

TOCO see Thiol-olefin co-oxygenation Tocopherols, TEARS assay, 668 Torsion angles, hydroperoxides, 690 Tosylhydrazones, superoxide reactions, 1036 Total hydroperoxides see Peroxide value Total oxidative capacity, titration methods, 674 Total polar phenols, colorimetry, 664 Toxicity... 

Butadiene has been co-oxidized with a number of aralkyl hydrocarbons and cyclic olefins. The order of increasing reactivity toward butadieneperoxy radicals (X—02—C H602) is cumene, sec-butylbenzene < cyclooctene < cyclohexene... 

Autoxidation of mercaptans gives rise to thiyl radicals, but these, like phenoxy radicals, are inert toward oxygen and normally dimerize to disulfides. Their participation in a chain reaction can be achieved in the co-oxidation of olefins and mercaptans, first demonstrated by Khar-asch (12), which takes advantage of the rapid addition of thiyl radicals to double bonds. 

Reaction 9) (15). We also found that the ease with which olefins are oxidized in the presence of [MCl(CO) (Ph3P)2] (M = Rh, Ir) increases with the degree of substitution (12). Reactivity follows the order ... 

Complex 33 was found to also catalyze the epoxidation of various disubstituted olefins with 02 as the primary oxidant and isobutyraldehyde as the sacrificial co-oxidant (Mukayama conditions Klement et al., 1997). Yields of 70-85% were obtained after heating the olefins and 33 under oxygen atmosphere in a mixture of toluene and 1-bromoperfluorooctane to 50 °C for 5-12 h, as exemplified in eq. 5.10 for the synthesis of cyclo-octeneoxide 34. The ruthenium was held back almost quantitatively in the fluorous phase and could be separated after cooling to 0°C and reused several times. 

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