Percarbonates, formation

Perborates, formation of, 28. Percarbonates, formation of, 22. Permanganates, formation of, 25. Persolpburio aoid, formation of, 17. Phenantbrene, oxidation of, 66. Potaaainm fenioyanide, 28. 

Mixing sodium percarbonate with acetic anhydride led to explosive shattering of the flask [1], undoubtedly caused by the formation of acetyl peroxide. The name sodium percarbonate has been used indiscriminately to describe 3 different compounds, all of which would react with acetic anhydride to give extremely explosive acetyl peroxide [2], These are sodium monoperoxycarbonate, NaOCO.OONa, [4452-58-8] sodium peroxydicarbonate, NaOCO.OOCO.ONa, [3313-92-6] and sodium carbonate sesqui hydrogen peroxidate, Na0C0.0Na.l,5H202, [15630-89-4],... 

The formation of peracids as the effective oxidizing species has often been proposed for oxidations with sodium percarbonate in the presence of organic acids or acid anhydrides30-32. It was observed that at room temperature and in dichloromethane as solvent, the addition of acetic anhydride induced the epoxidation by sodium perborate of mono-, di- and trisubstituted alkenes, including a,/i-unsaturated ketones in a slightly exothermic reaction33 (equation 6). 

Chiral pyrrolidine derivatives, proline, and amino acid-derived imidazolidinones mediate the asymmetric epoxidation of ,/i-unsalurated aldehydes. Protected a,a-diphenyl-2-prolinol catalyses the asymmetric formation of 2-epoxyaldehydes, with hydrogen peroxide or sodium percarbonate as the oxygen sources, with 81-95% conversion with up to 96 4 dr and 98% ee.204... 

Mixing sodium percarbonate with acetic anhydride led to explosive shattering of the flask [1], undoubtedly caused by the formation of acetyl peroxide. The name sodium... 

Petersen found that, if the solution was concentrated, the current strength exercised only a trifling influence on the decomposition phenomena in the electrolysis of sodium formate. According to Salzer s researches, formic acid in sulphuric-acid solution cannot completely suppress the evolution of oxygen at a platinized anode. Sodium formate is for the most part converted into carbonate in neutral solution small quantities of percarbonate are also formed. 

Sodium perborate has been recommended for the oxidation of alkenyldialkoxyboranes to aldehydes. In particular, the reagent avoids the formation of possibly hazardous 2 1 aldehyde-4iydrogen peroxide adducts as well as C—C bond cleavage. Sodium percarbonate is an air-stable solid, inexpensive and self-buffered, that appears to be a promising oxidant. ... 

Two advantages of CA[Mn] are a broader substrate range and the lack of aldehyde side products. CA[Mn] catalyzed epoxidation of fran.y-P-niethyl styrene (46% ee), but this substrate was not oxidized by CPO [57], We did not detect any aldehyde side products in the CA[Mn] catalyzed epoxidations. In contrast, the CPO and CiP-catalyzed epoxidation of styrene formed 24% [57] and 52% [55] benzaldehyde side product. These aldehyde side products form simultaneously with epoxide during styrene epoxidation catalyzed by heme peroxidases [55]. Althongh the mechanism of aldehyde formation is nnknown, this simultaneous formation of aldehyde suggests that it forms from a reaction intermediate of epoxidation. Since the mechanism of epoxidation for the CA[Mn] percarbonate reaction differs from that for the heme peroxidases, this different mechanism may account for the lack of aldehyde side products. 

The BDD anode has a very important role to play in the disinfection of water. Indeed, percarbonate persulfate and ozone can be generated by electrolysis directly from the water without adding chemicals. Note that the presence of chloride ions can provoke the formation of chloride species, which are dangerous for health. 

Initiation Formation of radicals from a hydrocarbon R — CH2 — R using initiators such as dibenzoyl peroxide, percarbonates, azobisisobutyronitrile (the radicals yielded by these initiators are generally written, R below)... 

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