Oxidation olefine to epoxide

Alkylsulfonic peracids oxidize olefins to epoxides. The formed sulfonic acid reacts with epoxide to form diols and esters. The yields of epoxides in the reactions of oxidation of two cycloolefins are given in Table 12.4. 

Incorporation of Cu(II) into the galleries of a-ZrP resulted in a catalyst that is active for the oxidation of carbon monoxide in the presence of oxygen, and the catalytic activity was comparable to that of a number of similar catalysts used for the oxidation of CO (129). Porphyrins and phthalocyanins intercalated into a-ZrP were used to oxidize olefins to epoxides by dioxygen, with considerable selectivity. While cyclohexene was oxidized to predominantly the epoxide and smaller amounts of allylic oxidation products, cis-stilbene gave rise to different... 

Harr1974 Harrison, C.R. and Hodge, P, Preparation of a Polymer-supported Per-acid and Its Use to Oxidize Olefins to Epoxides, J. Chem. Soc., Chem. Commun., (1974) 1009-1010. 

Could be described as two C-0 disconnections or as FGl (olefin to epoxide by oxidation). 

The Pacman catalyst selectively oxidized a broad range of organic substrates including sulfides to the corresponding sulfoxides and olefins to epoxides and ketones. However, cyclohexene gave a typical autoxidation product distribution yielding the allylic oxidation products 2-cyclohexene-l-ol (12%) and 2-cyclohexene-1-one (73%) and the epoxide with 15% yield [115]. 

The reactions of aldehydes at 313 K [69] or 323 K [70] in CoAlPO-5 in the presence of oxygen results in formation of an oxidant capable of converting olefins to epoxides and ketones to lactones (Fig. 23). This reaction is a zeolite-catalyzed variant of metal [71-73] and non-metal-catalyzed oxidations [73,74], which utilize a sacrificial aldehyde. Jarboe and Beak [75] have suggested that these reactions proceed via the intermediacy of an acyl radical that is converted either to an acyl peroxy radical or peroxy acid which acts as the oxygen-transfer agent. Although the detailed intrazeolite mechanism has not been elucidated a similar type IIaRH reaction is likely to be operative in the interior of the redox catalysts. The catalytically active sites have been demonstrated to be framework-substituted Co° or Mn ions [70]. In addition, a sufficient pore size to allow access to these centers by the aldehyde is required for oxidation [70]. 

Alkyl hydroperoxides, including ethyl hydroperoxide, cuminyl hydroperoxide, and tert-butyl hydroperoxide, are not used by V-BrPO to catalyze bromination reactions [29], These alkyl hydroperoxides have the thermodynamic driving force to oxidize bromide however, they are kinetically slow. Several examples of vanadium(V) alkyl peroxide complexes have been well characterized [63], including [V(v)0(OOR)(oxo-2-oxidophenyl) salicylidenaminato] (R = i-Bu, CMe2Ph), which has been used in the selective oxidation of olefins to epoxides. The synthesis of these compounds seems to require elevated temperatures, and their oxidation under catalytic conditions has not been reported. We have found that alkyl hydroperoxides do not coordinate to vanadate in aqueous solution at neutral pH, conditions under which dihydrogen peroxide readily coordinates to vanadate and vanadium( V) complexes (de la Rosa and Butler, unpublished observations). Thus, the lack of bromoperoxidase reactivity with the alkyl hydroperoxides may arise from slow binding of the alkyl hydroperoxides to V-BrPO. 

Coordination catalysis via alkyl hydroperoxides is well documented (4, 31). Selective oxidations of olefins to epoxides (Reaction 16), using especially Group IV, V, and VI transition-metal complexes, can occur possibly via oxygen-transfer processes of the type... 

Another possibility for enhaneing the selectivity toward epoxides is use of the urea-H202 (UHP) adduct. This enables the oxidation to be carried out in water-free solutions, thus avoiding formation of any diols and other side reactions. In the case of the oxidation of chiral allylic alcohols (see below) high diastereo-selectivities have been achieved [3]. The ability to transform olefins to epoxides diastereoselectively seems to indicate that the reaction proceeds through a peracid-like transition state. However, a drawback of the urea-H202 system is the insolubility of the polymeric complex. 

R. G. Bowman, Silver-based catalyst for vapor phase oxidation of olefins to epoxides, US Patent 4,845,253, July 4,1989, To The Dow Chemical Company. 

The literature on the use of organic per acids for the oxidation of olefins, especially higher olefins, to epoxides and glycols has been surveyed by Swern (112),... 

Without attempting to be exhaustive, we will try in this chapter to focus on results allowing us to directly oxidize olefins to their corresponding epoxide, using microbial cells. Other sources of monooxygenases, such as mammalian cells (micro-somes) or plant cells, have been studied in this respect. However, these will not be considered in this review. 

In continuation to our studies with molecular oxygen as the primary oxidant[8], we now report metal phthalocynanine catalyzed oxidation of sulphides to sulphones and olefins to epoxides by dioxygen-isobutyraldehyde system under ambient conditions (Scheme-1). 

In conclusion Fe(II), Mn(II) and Co(II)tetrasulphonato- phthalocyanine catalysed oxidation with molecular oxygen using isobutyraldehyde as sacrificial agent offers an simple and nonhazardous synthetic tool for the oxidation of sulphides to sulphones and olefins to epoxides. As these metal phthalocyanine are largely insoluble in dichloroethane type solvents, they can be recovered by filtration and reused. The isobutyric acid formed as byproduct in these reactions can be largely recovered by distillation when the reaction carried out at large scale. 

The polymer-bound peracid described by Frichet et al. which was easily obtained by H Oj oxidation of die corresponding benzoic acid can be used to oxidise olefins to epoxides. The purification is achieved by simple filtration of the polymer-bound reagent, which can be recycled and re-used. It has to be pointed out, however, that after a few reaction cycles the reagent looses some of its initial activity. Nevertheless, this example demonstrates nicely the potential of polymer-bound reagents in combinatorial organic synthesis (COS) (more examples will be presented in Chapter 1.6). 

Recently, Choudary et al. reported the asymmetric epoxidation of unfunctionalized olefins to epoxides using manganese acetylacetonate stabilized on nanocrystalline magnesium oxide in the presence of (IR, 2R)-(—)-diaminocyclohexane (DAC) as a chiral ligand in good yields and up to 91% enantiomeric excess (Scheme 5.7). ... 

It is also possible to load metals into the nanocrystalline magnesium oxide, such that very high dispersions are possible, which serve as an unusual catalyst support. The asymmetric epoxidation (AE) of unfunctionalized olefins to epoxides using manganese acetylacetonate stabilized on NAP-MgO has been described. 

The most widely used reaction in this category is the conversion of olefins to epoxides. In most cases, one of several peroxycarboxylic acids is used to effect oxidation. m-Chloroperoxybenzoic acid, which is commercially available or readily prepared and is a quite stable solid, is the most popular reagent. Peroxyacetic acid, peroxybenzoic acid, peroxytrifluoroacetic acid, and others, however, have also been used frequently. 

The metal ion catalyzed oxidation of aldehydes to carboxylic acids has been extensively studied and a free-radical chain mechanism is now firmly established. The acylperoxy radical intermediate has been utilized for converting olefins to epoxides. 

The compound [Mocp(CO)3]2 catalyzes oxidation of substituted olefins to epoxides and allyl alcohols, while in the presence of [Vcp(CO)4] epoxy alcohols are formed [equation (9.167)]. 

Molybdenum hexacarbonyl-catalyzed hydroperoxide oxidation of olefins to epoxides [127]. 

The addition of an oxygen atom to an olefin to generate an epoxide is often catalyzed by soluble molybdenum complexes. The use of alkyl hydroperoxides such as tert-huty hydroperoxide leads to the efficient production of propylene oxide (qv) from propylene in the so-called Oxirane (Halcon or ARCO) process (79). 

Sulfurane reagent lor conversion of trans diols to epoxides, generally for dehydration of diols to olefins or cyclic ethers, and as an oxidizing agent... 

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