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The reaction proceeds through what is commonly known as the "butterfly mechanism", first proposed by Bartlett, wherein the peracid is intramolecularly hydrogen-bonded at the transition state. [5] Although there are frontier orbital interactions in both directions, the peracid is generally viewed as the electrophile and the alkene as the ...
meta-Chloroperoxybenzoic acid (mCPBA or mCPBA) is a peroxycarboxylic acid. It is a white solid often used widely as an oxidant in organic synthesis. mCPBA is often preferred to other peroxy acids because of its relative ease of handling. [1] mCPBA is a strong oxidizing agent that may cause fire upon contact with flammable material. [2]
Through a concerted mechanism, one of the substituents on the ketone group migrates to the oxygen of the peroxide group while a carboxylic acid leaves. [1] This migration step is thought to be the rate determining step. [2] [3] Finally, deprotonation of the oxocarbenium ion produces the ester. [1] Reaction mechanism of the Baeyer-Villiger ...
In the elimination reaction, all five participating reaction centers are coplanar and, therefore, the reaction stereochemistry is syn. Oxidizing agents used are hydrogen peroxide, ozone or MCPBA. This reaction type is often used with ketones leading to enones. An example is acetylcyclohexanone elimination with benzeneselenylchloride and sodium ...
Although less active than more acidic peracids (e.g., m-CPBA), peracetic acid in various forms is used for the epoxidation of various alkenes (Prilezhaev reaction). Useful applications are for unsaturated fats, synthetic and natural rubbers, and some natural products such as pinene. A variety of factors affect the amount of free acid or ...
However it has been shown that for medium-sized rings (eight and nine) peracid oxidizers show reverse selectivity, while vanadium catalyzed reactions continue to show formation of the syn epoxide. [14] Although it is the least reactive metal catalyst for epoxidations, vanadium is highly selective for alkenes with allylic alcohols.
Because this reaction consumes base and active oxidant, two equivalents of base and oxidant are necessary under weakly basic conditions. A unified mechanism under neutral and basic conditions in presented in a recent article. [6] The authors present a comprehensive analysis of a number of oxoammonium salt mediated oxidations. (2)
This mechanism, which was originally proposed by John Groves to explain porphyrin-catalyzed epoxidation reactions, [9] is commonly referred to as a "side-on perpendicular approach". The approach is over the diamine bridge, where the steric bulk of the tert-butyl groups on the periphery of the ligand do not interfere with the alkene's approach ...