Phthaloyl peroxide

The rather stable diacyl peroxides such as dibenzoyl or phthaloyl peroxide have attracted special interest as some of their reactions, mostly not chain reactions, are chemiluminescent. Triplet-singlet energy transfer is very often involved, and emission generally occurs only when a fluorescer is present since the primary excited products cannot emit in the visible range of the spectrum. 

DPA) in dimethylphthalate at about 70°, yields a relatively strong blue Umax =435 nm) chemiluminescence the quantum yield is about 7% that of luminol 64>. The emission spectrum matches that of DPA fluorescence so that the available excitation energy is more than 70 kcal/mole. Energy transfer was observed on other fluorescers, e.g. rubrene and fluorescein. The mechansim of the phthaloyl peroxide/fluorescer chemiluminescence reaction very probably involves radicals. Luminol also chemiluminesces when heated with phthaloyl peroxide but only in the presence of base, which suggests another mechanism. The products of phthaloyl peroxide thermolysis are carbon dioxide, benzoic acid, phthalic anhydride, o-phenyl benzoic acid and some other compounds 65>66>. It is not yet known which of them is the key intermediate which transfers its excitation energy to the fluorescer. 

Bis(fluoroformyl) peroxide, 0625 Bis-3-(2-furyl)acryloyl peroxide, 3640 Bis(trichloroacetyl) peroxide, 1361 Bis(trifluoroacetyl) peroxide, 1367 Diacetyl peroxide, 1537 Dibenzenesulfonyl peroxide, 3499 Dibenzoyl peroxide, 3639 Di-3-camphoroyl peroxide, 3807 Dicrotonoyl peroxide, 2986 Dicyclohexylcarbonyl peroxide, 3667 Didodecanoyl peroxide, 3857 Di-2-furoyl peroxide, 3245 Dihexanoyl peroxide, 3554 Diisobutyryl peroxide, 3032 Diisopropyl peroxydicarbonate, 3034 Dimethanesulfonyl peroxide, 0931 Di-2-methylbutyryl peroxide, 3354 Di-l-naphthoyl peroxide, 3831 3,6-Dioxo-l,2-dioxane, 1445 Dipropionyl peroxide, 2442 Dipropyl peroxydicarbonate, 3035 Di-4-toluenesulfonyl peroxide, 3656 Peroxodisulfuryl difluoride, 4328 Phthaloyl peroxide, 2900 Potassium benzenesulfonylperoxosulfate, 2257 Potassium O-O-benzoylmonoperoxosulfate, 2684 (9-TriIIuoroacctyl-.S -lluorofonny 1 thioperoxide, 1050 See PEROXIDES, PEROXYCARBONATE ESTERS... 

The oxidation of organic substances by cyclic peroxides has been intensively studied over the last decades , from both the synthetic and mechanistic points of view. The earliest mechanistic studies have been carried out with cyclic peroxides such as phthaloyl peroxide , and more recently with a-methylene S-peroxy lactones and 1,2-dioxetanes . During the last 20 years, the dioxiranes (remarkable three-membered-ring cyclic peroxides) have acquired invaluable importance as powerful and mild oxidants, especially the epoxidation of electron-rich as well as electron-poor alkenes, heteroatom oxidation and CH insertions into alkanes (cf. the chapter by Adam and Zhao in this volume). The broad scope and general applicability of dioxiranes has rendered them as indispensable oxidizing agents in synthetic chemistry this is amply manifested by their intensive use, most prominently in the oxyfunctionalization of olefinic substrates. 

Steinfatt proposed an alternative mechanism for the formation of excited aminophth-alate, based on the concept of dioxirane-carbene mediated chemiexcitation, which is also attributed to other chemiluminescent systems ° °. After the attack of hydrogen peroxide on the diazaquinone 27 carbonyl carbon, a perhydrolysis step is postulated to result in the intramolecular dioxirane-carbene system (32) in the excited state ° ° . This species presumably rearranges to 3-aminophthalate dianion while still in the singlet-excited state (Scheme 23). Although this is a very interesting mechanistic proposal, it is based on experimental evidence obtained with indirect phthaloyl peroxide chemiluminescence and no further evidence corroborates this proposal. 

Phthalein dyes, hydrogen peroxide determination, 628-9 Phthaloyl peroxide, luminol chemilumine scence, 1245 Physiological matrices... 

The first direct infrared (IR) spectroscopic detection of o-benzyne was accomplished by Chapman et al., " using matrix isolation spectroscopy at very low temperatures to generate 4 starting from phthaloyl peroxide (5) and benzocyclo-... 

Benz-2-oxetanone, a very unstable molecule, has been prepared in an argon matrix at 8 K by irradiation of phthaloyl peroxide (equation 117) (73JA4061). 

Cyclic peroxides may serve as a source of singlet oxygen. Wasserman et reacted 9,10-diphenylanthracene peroxide (238, conveniently prepared as in Nilsson and Kearns ) with 138 to give 140 rubrene peroxide proved to be considerably less efficient. Decomposition of anthracene peroxide alone takes another course. 32.396 jg treated with phthaloyl peroxide... 

Phthaloyl peroxide (509) has similarly been employed as a precursor of benzyne (510)446 A careful examination in an argon matrix at 8 K has revealed that the /(-lactone (511) and the keto ketene (512) are intermediates... 

Dipropionyl peroxide, 2436 Dipropyl peroxydicarbonate, 3030 Peroxodisulfuryl difluoride, 4322 Phthaloyl peroxide, 2895 Potassium benzenesulfonylperoxosulfate, 2250 Potassium O—O-benzoylmonoperoxosulfate, 2680 O-Trifluoroacetyl-S -fluoroformyl thioperoxide, 1047 See PEROXIDES, PEROXYCARBONATE ESTERS... 

By contrast, the formation of arynes in the vapor phase has received scant attention. Wittig (1961) pyrolyzed bisiodophenylmercury (2) and phthaloyl peroxide (3) in argon at 600° and 5 torr and obtained 54% and 27% yields, respectively, of biphenylene (4) ... 

The synthesis of fused oxetane derivatives via the Paterno-Bchi cycloaddition of carbonyls and alkenes is discussed in detail in a representative example is shown in Scheme 7 <2001CEJ4512>. See also Sections 3.3.1.8.3 and 3.4.1.10.5 for the preparation of fused oxetanes and azetdines by [2 + 2] cycloaddition reactions. Benzox-etan-2-one 10 has been prepared in an argon matrix by C02 loss from phthaloyl peroxide <1973JA4061>. 

Though many open-chain diacyl peroxides have been described, very few cyclic compounds of this type are known. Monomeric cyclic phthaloyl peroxide (84) is prepared by treatment of phthaloyl chloride in chloroform with aqueous sodium peroxide solution in the presence of phosphate buffer, or by reaction of phthaloyl chloride with ethereal hydrogen peroxide in the presence of sodium carbonate.70-72 Russell71 has also obtained cyclic diacyl peroxides from the dichlorides of the C10, C12, and C14 dicarboxylic acids. Only polymeric diacyl peroxides were obtained from lower dicarboxylic acids. 

The decomposition of 84 in dimethylaniline was studied by Horner and Briiggemann.74 Greene has published a number of papers on the chemical behavior of the cyclic phthaloyl peroxide (84).72,75-79... 

Cyclic phthaloyl peroxide (84) reacts with olefins in bimolecular, nonradical reactions, which are first order with respect to peroxide and olefin.78 These reactions begin with an electrophilic attack on the double bond by the peroxide. 

State they have more than sufficient energy. The excited singlet state of pyrene sensitises the decomposition of [122] and phthaloyl peroxide (Horn and Schuster, 1979). By means of the technique of flash photolysis it was possible to show that these sensitisation reactions produced the pyrene radical cation and heme that the CIEEL mechanisms was operating. 

Phthaloyl peroxide (2.93) on photolytic decomposition generates benzyne via lactone intermediate. 

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