Epoxides Prilezhaev reaction

The Prilezhaev reaction is a rarely used name for the epoxidation of an alkene 1 by reaction with a peracid 2 to yield an oxirane 3. The epoxidation of alkenes has been further developed into an enantioselective method, that is named after Sharpless. 

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]. 

The Prilezhaev reaction is stereospecific, and a syn addition of the oxygen to the double bond is observed in all cases. This observation supports the assumption that the epoxidation of alkenes by peroxyacids is a concerted process. The reaction takes place at the terminal oxygen atom of the peroxyacid, and the n HOMO of the olefin approaches the o LUMO of the 0-0 bond at an angle of 180° (butterfly transition structure). 

Prilezhaev reaction Oxidation of alkenes to epoxides using peroxycarboxylic acids. 362... 

Related reactions Jacobsen-Katsuki epoxidation, Prilezhaev oxidation, Rubottom oxidation, Sharpless asymmetric epoxidation, Shi... 

Related reactions Davis oxaziridine oxidation, Prilezhaev reaction, Sharpless asymmetric epoxidation, Shi asymmetric epoxidation ... 

Prilezhaev reaction The formation of an epoxide from the reaction of perbenzoic acid on an alkene. 

Chiral peroxy acids, such as monoperoxycamphoric acid, have been used in a classical Prilezhaev reaction for the preparation of chiral epoxides [1], however, the enantiomeric excess (e.e.) of the epoxides formed was below 10%,... 

We began our work with isoprene alcohol (see Scheme 11). While the Prilezhaev reaction with monoperoxyphthalic acid provided the appropriate dimethyl glycidol in good yield, we failed in our attempts to prepare the corresponding chiral epoxide by Sharpless epoxidation. Obviously, the reaction does not work in the case of this tertiary allylic alcohol. When the solution is allowed to warm up to room temperature a slow epoxidation takes place, however, the isolated dimethyl glycidol does not show any optical activity. Very recently the asymmetric epoxidation of a tertiary allylic alcohol in reasonable optical and chemical yield has been described [21]. 

The Prilezhaev reaction is the formation of epoxides by the reaction of alkenes with peracids. 

In synthetic studies toward the natural poduct diazonamide A, Nicolaou and coworkers utilized several Prilezhaev reactions. Two examples are shown below compounds 23 and 25 were epoxidized using m-CPBA to yield 24, and 26, respectively.17... 

In synthetic studies on isoprenoid aziridines, Coates and co-workers utilized several Prilezhaev reactions to synthesize epoxides which were reacted with diethylaluminum azide to form azidohydrins.19 Two examples are shown below compounds 27 and 29 were epoxidized using m-CPBA to yield 28 and 30, respectively. 

Martin and co-workers utilized the Prilezhaev reactions to synthesize epoxides 32 and 33. Epoxidation with m-CPBA gave in 96% yield an inseparable mixture of epoxides 32/33 in a 2 3 ratio.20... 

Prilezhaev reaction (epoxidation of olefins) Additive oxidation... 

The reaction of olefin epoxidation by peracids was discovered by Prilezhaev [235]. The first observation concerning catalytic olefin epoxidation was made in 1950 by Hawkins [236]. He discovered oxide formation from cyclohexene and 1-octane during the decomposition of cumyl hydroperoxide in the medium of these hydrocarbons in the presence of vanadium pentaoxide. From 1963 to 1965, the Halcon Co. developed and patented the process of preparation of propylene oxide and styrene from propylene and ethylbenzene in which the key stage is the catalytic epoxidation of propylene by ethylbenzene hydroperoxide [237,238]. In 1965, Indictor and Brill [239] published studies on the epoxidation of several olefins by 1,1-dimethylethyl hydroperoxide catalyzed by acetylacetonates of several metals. They observed the high yield of oxide (close to 100% with respect to hydroperoxide) for catalysis by molybdenum, vanadium, and chromium acetylacetonates. The low yield of oxide (15-28%) was observed in the case of catalysis by manganese, cobalt, iron, and copper acetylacetonates. The further studies showed that molybdenum, vanadium, and... 

Direct Oxidation with Stoichiometric Oxidants. Discovered by Prilezhaev in 1909,211 the typical epoxidation reaction of alkenes is their oxidation with organic peracids. Of the large number of different peroxycarboxylic acids used in... 

The reaction of alkenes with peroxycarboxylic acids to produce epoxides was discovered by Prilezhaev over 80 years ago.14 It is still the most widely used method for epoxidation, and considerable work has been carried out to elucidate the mechanism. The commonly accepted explanation for oxirane formation involves a cyclic polar process where the proton is transferred intramolecularly to the carbonyl oxygen, with simultaneous attack by the alkene rc-bond. This concerted process was suggested by Bartlett,15 and because of the unique planar transition structure it is referred to as the butterfly mechanism (Figure 3.2). 

Perhaps the most common method for the epoxidation of simple alkenes is their reaction with peroxyacids, which has occasionally been referred to as the Prilezhaev (Prileschajew) reaction. O This reaction does not require transition metal catalysis and the yield of epoxide is often high. Peroxyacids such as 156 are prepared by reaction of carboxylic acids with hydrogen peroxide. An equilibrium is established during the reaction that favors the peroxyacid, although several alternative methods are available.279 in general, strong... 

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