Reaction with acyl peroxides

Hydroxyall l Hydroperoxyall l Peroxides. There is evidence that hydroxyalkyl hydroperoxyalkyl peroxides (2, X = OH, Y = OOH) exist in equihbrium with their corresponding carbonyl compounds and other a-oxygen-substituted peroxides. For example, reaction with acyl haUdes yields diperoxyesters. Dilute acid hydrolysis yields the corresponding ketone (44). Reduction with phosphines yields di(hydroxyalkyl) peroxides and dehydration results in formation of cycHc diperoxides (4). 

Reaction of acyl peroxides with copper azide... 

Decomposition of azo compounds and peroxides provides the alkoxyamine by the nitroxide-trapping of the primary radicals [29]. The radicals produced by hydrogen abstraction with oxy radicals are also trapped by the nitroxide [242, 243]. In the photoreaction, alkoxyamines were isolated with high yields [244]. The reactions of Grignard reagents with nitroxides [215] and the coupling reaction of sodium nitroxides with bromo compounds [234,235] are also used. The hydrolysis of 56 followed by the reaction with acyl or alkyl halides afforded alkoxyamines with various functional groups,63 (Eq. 68) [245-251] ... 

Reaction of CP2V with acyl peroxides is complex . One can observe [CpV(p-... 

Di-tert-butyl peroxide Reactions with acyl radicals Acylhydrazines... 

A. Reaction with Acyl Chlorides and Esters. In view of the facile reaction of 62 with alkyl halides, it is not unexpected that acyl halides should react rapidly with 02. Johnson (22) has reported that diacyl peroxides are conveniently produced in the reaction of KO2 with acyl chlorides according to... 

The effect of activators like FeS04 [11,12] for emulsion polymerization and ferric stearate [13] for bulk polymerization of vinyl monomers in combination with acyl peroxide has been studied. The ferrous ion catalyzed decomposition of BZ2O2 in ethanol has been studied in some detail by Has-egawa and co-workers [14,15]. The cycle, which requires reduction of Fe " by solvent-derived radicals, yields a steady-state concentration of Fe after a few minutes, shown spectroscopically to be proportional to the initial concentration of the ferrous ion [14]. The second-order rate o)nstant for the following reaction was found to be 8.4 L moP sec at 25 C, with an activation energy of 14.2 kcal moP ... 

The R—C— O radical, reaction (16), and R—C—00 radical, reaction (17), may react with acyl peroxide as follows ... 

The presence of free radicals in the reaction of tertiary amines and benzoyl peroxide has been observed by electron spin resonance (ESR) spectroscopy [67-69]. The reaction of amines with acyl peroxide is much more rapid than the thermal decomposition of the peroxide alone [70]. For example, benzoyl peroxide [53] with dimethylaniline at 0 C in styrene or chloroform exhibits an apparent second-order rate constant of 2,3 X 10 sec However, acetyl [41] and lauroyl peroxide [71,72] react somewhat slower. 

II Reaction of diorganotin hydrides with acyl-peroxides. 

Synthesis. Symmetrical diacyl peroxides (20, R = R = alkyl or aryl) are prepared by the reaction of an acyl chloride or anhydride with sodium peroxide or hydrogen peroxide and a base ... 

Potassium salts of the peroxides (27—29) are prepared from the reaction of Caro s acid [7722-86-3] H2SO, with acyl chlorides, chloroformates, or organosulfonyl chlorides in the presence of potassium hydroxide (44). 

At low temperature a 1 1 adduct of thioacetic acid and an enamine could be prepared (709). The previously described reaction of aminomethylene ketones with hydrogen peroxide was extended to bisaminomethylene compounds. However, acylated cyclohexenamines led to cyclopentane-carboxamides (770), Trichloromethyl adducts of enamines and the rearranged amine derivatives were described in a further study (777). 

A heterocyclic ring may be used in place of one of the benzene rings without loss of biologic activity. The first step in the synthesis of such an agent starts by Friedel-Crafts-like acylation rather than displacement. Thus, reaction of sulfenyl chloride, 222, with 2-aminothiazole (223) in the presence of acetic anhydride affords the sulfide, 224. The amine is then protected as the amide (225). Oxidation with hydrogen peroxide leads to the corresponding sulfone (226) hydrolysis followed by reduction of the nitro group then affords thiazosulfone (227). ... 

The experimental data on the reactions of ketyl radicals with hydrogen and benzoyl peroxides were analyzed within the framework of IPM [68]. The elementary step was treated as a reaction with the dissociation of the O—H bond of the ketyl radical and formation of the same bond in acid (from acyl peroxide), alcohol (from alkyl peroxide), and water (from hydrogen peroxide). The hydroperoxyl radical also possesses the reducing activity and reacts with hydrogen peroxide by the reaction... 

Anderson, L. R. et al., J. Fluorine Chem., 1976, 7, 481-500 Five derivatives, including the 0-0 lithium or sodium salts of the hydrogen peroxide adduct of hexafluoroacetone (2-hydroxyhexafluoro-2-propyl hydroperoxide), and their reaction products with acyl halides, are less flammable or explosive than their hydrocarbon analogues, though less stable than the parent hydroperoxides. Relevant entries are ... 

Reactions of O2 with esters R C(0)0R also pass nucleophilic substitution as an initial step (Sawyer and Gibian 1979). Final products are acyl peroxides or carboxylic acids. The following set of equations explains the product formation ... 

With radical sources other than acyl peroxides, the rearomatization of the a-complex can take place by various, not always well characterized, reactions, such as oxidation by metal salts, hydrogen abstraction by intermediate radicals, disproportionation, and induced decomposition. 

Reaction with acetyl chloride yields diacetyl peroxide. Similar diacyl peroxides are formed from other acyl chlorides ... 

In this section we discuss the thermochemistry of some species with the general formulas, RC(=0)00H, RC(=0)00R and RC(=0)00C(=0)R. These species have the generic names peracids (peroxycarboxyUc acids), peresters (percarboxylate esters) and acyl peroxides. The enthalpy of formation values are in Table 3. Three formal reactions that are discussed here are conceptually the same as in the earlier sections. Because now there is a carbonyl group present, we rewrite equations 5, 6 and 9 as equations 14, 15 and 16. 

The oxidation of nonfluorinated aromatic amines with free peracids (not acyl peroxides) proceeded best with the basic amines. The reaction did not pass through the azo stage of oxidation since azo compounds could not be converted under the reaction conditions and hydrazo compounds were oxidized to azo compounds. Under the reaction conditions, p-toluidine was converted only into p-nitrotoluene [31]. 

---