Epoxides from olefins

The Jacobsen-Katsuki epoxidation reaction is an efficient and highly selective method for the preparation of a wide variety of structurally and electronically diverse chiral epoxides from olefins. The reaction involves the use of a catalytic amount of a chiral Mn(III)salen complex 1 (salen refers to ligands composed of the N,N -ethylenebis(salicylideneaminato) core), a stoichiometric amount of a terminal oxidant, and the substrate olefin 2 in the appropriate solvent (Scheme 1.4.1). The reaction protocol is straightforward and does not require any special handling techniques. 

Some doubt was cast oh these observations, however, when it was shown555 that vitamin A alcohol undergoes autoxidation in the dark" u give the epoxide of vitamin A alcohol. The ability of manganese iioxide to produce epoxides from olefins is therefore still open to... 

It should be noted that the related imine-oxaziridine couple E-F finds application in asymmetric sulfoxidation, which is discussed in Section 10.3. Similarly, chiral oxoammonium ions G enable catalytic stereoselective oxidation of alcohols and thus, e.g., kinetic resolution of racemates. Processes of this type are discussed in Section 10.4. Whereas perhydrates, e.g. of fluorinated ketones, have several applications in oxidation catalysis [5], e.g. for the preparation of epoxides from olefins, it seems that no application of chiral perhydrates in asymmetric synthesis has yet been found. Metal-free oxidation catalysis - achiral or chiral - has, nevertheless, become a very potent method in organic synthesis, and the field is developing rapidly [6]. 

See also Ethers and Epoxides from Olefins (Section 13 ) and Ketones from Ethers and Epoxides (Section 174). 

Perbenzoic acid is an important reagent for the preparation of epoxides from olefinic compounds (method 126). When the epoxides are unstable in aqueous solution, glycols ate formed directly. The over-all reaction results in trans addition of hydrcscy groups to the double bond for crotonic and isocrotonic acids. ... 

G. H. Grosch, U. Muller, M. Schulz, N. Richer, H. Wurz, Oxidation catalyst and process for the production of epoxides from olefines, hydrogen and oxygen using said oxidation catalyst, U.S. Patent No. 6,008,389,1999, Assigned to BASF Corporation. 

It is known that titania/silica can catalyze oxidation reactions [1-3]. Especially, titanium-silicate-1 (TS-1) has been shown to be a very effective catalyst for oxidation reactions. In the TS-1 catalyst, most Ti atoms are isolated from each other by long chains of -O-Si-O-Si-0- and this structure gives high selectivity for the formation of epoxides from olefins [1]. 

Heterocyclic Ring Formation-H202, in the presence of isocyanate as CO-reactant, yields epoxides from olefins in 50-75% yield. This system is advantageous when reactions must be conducted in neutral medium. 1,2-Ditosylates afford... 

G. Thiele, Process for the Preparation of Epoxides from Olefins, Vol. US Patent 6,372,924 B2, To Degussa-Huls AG. 

Figure 11.6 Formation of bromohydrins and epoxides from olefins in water.

ETHERS AND EPOXIDES FROM OLEFINS H2O2 MeCN... 

The discussion in previous Section 9.3 focused on classic oxidative methods for the synthesis of optically active epoxides from olefins. Oxiranes have long been recognized to be of great utility as chiral building blocks, and indeed their pervasive use attests to their central role in synthesis. Because the developments in epoxidation methods are closely linked to their applications, the section below presents selected transformations of epoxides that have been landmarks in the evolution of the field [30-33]. 

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