Diacetyl Peroxide Research Articles

Methyl Radical Initiated Kharasch and Related Reactions

AbstractAn improved procedure to run halogen atom and related chalcogen group transfer radical additions is reported. The procedure relies on the thermal decomposition of di‐tert‐butylhyponitrite (DTBHN), a safer alternative to the explosive diacetyl peroxide, to produce highly reactive methyl radicals that can initiate the chain process. This mode of initiation generates byproducts that are either gaseous (N2) or volatile (acetone and methyl halide) thereby facilitating greatly product purification by either flash column chromatography or distillation. In addition, remarkably simple and mild reaction conditions (refluxing EtOAc during 30 minutes under normal atmosphere) and a low excess of the radical precursor reagent (2 equivalents) make this protocol particularly attractive for preparative synthetic applications. This initiation procedure has been demonstrated with a broad scope since it works efficiently to add a range of electrophilic radicals generated from iodides, bromides, selenides and xanthates over a range of unactivated terminal alkenes. A diverse set of radical trap substrates exemplifies a broad functional group tolerance. Finally, di‐tert‐butyl peroxyoxalate (DTBPO) is also demonstrated as alternative source of tert‐butoxyl radicals to initiate these reactions under identical conditions which gives gaseous by‐products (CO2).magnified image

ChemInform Abstract: Structural Analysis of Pyrrolidinones.

In the course of a study on pyrrolidinones, the crystal structures of four compounds, namely, methyl N-[(4-meth­oxy­phenyl)(3,4,5-tri­meth­oxy­phenyl)­methyl]­pyro­glut­amate, C23­H27­NO7, methyl N-[naphthyl-(3,4,5-tri­meth­oxy­phenyl)­methyl]­pyro­glut­amate diacetyl peroxide, C26­H27­NO6·-0.5C4H6O4, 5-(3,4,5-tri­meth­oxy­phenyl)-1,2,3,11b-tetrahy­dro-5H-naphtho­[1,8-f,g]indol­izin-3-one, C24­H23­NO4, and 5-(3,4,5-tri­meth­oxy­phenyl)-1,2,3,5,12,12a-hexa­hydro­naph­tho­[1,2-f]indol­izine-3,12-dione, C25­H23­NO5, are presented, compared and discussed.

Addition Reactions of Alkyl and Carboxyl Radicals to Vinylidene Fluoride

The addition reactions of alkyl radicals CF3* and CH3* and carboxyl radicals C2H5O*, C2H5OCOO*, CF3COO*, and CH3COO* to a vinylidene fluoride (VDF) molecule are studied using ab initio calculations. These radicals were selected because they are intermediate or final products of diacyl peroxides decomposition in the initiation reactions of VDF polymerization. Two combinations of methods for energetics and structure optimization are applied: QCISD/6-311G(d,p)//HF/6-31G(d) and B3LYP/6-311G+(3df, 2p)//B3LYP/6-31G(d). It is found that the formed bond length of the product, the forming bond length of the transition state, and the attack angle of the product structures are not sensitive to the level of theory even though the attack angle of the transition state structures is. Early transition states are obtained upon attack at both high-substituted and nonsubstituted carbon atom VDF ends. Kinetic and thermodynamic control rules play different roles on governing the reactivity of the addition with the studied radicals. Both theoretical methods yield the same trends for the preferential attack site in terms of regioselectivity, barrier energies, and reaction enthalpies. It is shown that the addition reactions of the intermediate radicals C2H5OCOO*, CF3COO*, and CH3COO* of the decomposition of diethyl peroxydicarbonate, trifluoroacetyl peroxide, and diacetyl peroxide initiators yield smaller energy barriers than the additions of the corresponding final radicals, C2H5O*, CF3*, and CH3*; therefore, the reactions of the intermediate radicals should not be ignored when analyzing the initiation process of the VDF polymerization using those initiators.

Oxidative Cleavage of Carbon?Carbon Triple Bond ? A Review

Oxidation of phenylacetylene with molecular oxygen led to the formation of 10 oxygen containing products along with dimerisation, oligomerisation and polymerisation products. Benzaldehyde, benzoic acid and benzoic anhydride are the main oxidation products. The autoxidation of diphenylacetylene gives benzil as the main product and its yield increases upon use of ditertiary-butylperoxide as initiator. Examination of the crude oxidation mixtures of 1-phenylalk-1-ynes revealed the presence of corresponding α-dicarbonyl compounds in small quantities along with typical products like benzil, benzoic anhydride and phenyl benzoate. Similar oxidation of 1-phenylalkan-1,2-diones also yielded benzoic acid and the lower carboxylic acids as in the case of the corresponding 1-phenyl-1-alkynes and the oxidation is faster than the corresponding acetylenes. α-Dicarbonyl compounds undergo photochemical dissociation to free radicals in diffuse daylight but a thermal dissociation under the experimental conditions is not noted. Phenylglyoxal is regarded as one of the intermediates of phenylacetylene autoxidation. The formation of benzoic acid in all cases and considerable amounts of benzil from 1-phenyl-propane-1,2-dione and 1-phenyl-butane-1,2-dione in the thermal decomposition at 130° in presence of dibenzoyl peroxide, diacetyl peroxide or di-tert-butyl peroxide using chlorohenzene as solvent show that the reactions of the type Ph-CO-CO-R + X_ → Ph-CO_ + R-CO-X (with X_ = R'-O_ or R'-CO-O_) take place during the course of autoxidation of α-diketones. The products expected from the reaction of the short lived intermediate ketocarbenes with oxygen i.e. α-dicarbonyl compounds and lower carboxylic acids, especially benzoic acid were not detected in the thermal and photochemical decomposition of α-diazoacetophcnone, α-diazopropiophenone, α-diazobutyrophenone and a-diazodesoxyhenzoin. This shows that the oxidative scission of the C≡C bond proceeds via the corresponding α-dicarbonyl compounds as intermediates and not via the corresponding oxirenes or the valence isomeric ketocarbenes.

Oxidative cleavage of carbon-carbon triple bond - a-review

Oxidation of phenylacetylene with molecular oxygen led to the formation of 10 oxygen containing products along with dimerisation, oligomerisation and polymerisation products. Benzaldehyde, benzoic acid and benzoic anhydride are the main oxidation products. The autoxidation of diphenylacetylene gives benzil as the main product and its yield increases upon use of ditertiary-butylperoxide as initiator. Examination of the crude oxidation mixtures of 1-phenylalk-1-ynes revealed the presence of corresponding α-dicarbonyl compounds in small quantities along with typical products like benzil, benzoic anhydride and phenyl benzoate. Similar oxidation of 1-phenylalkan-1,2-diones also yielded benzoic acid and the lower carboxylic acids as in the case of the corresponding 1-phenyl-1-alkynes and the oxidation is faster than the corresponding acetylenes. α-Dicarbonyl compounds undergo photochemical dissociation to free radicals in diffuse daylight but a thermal dissociation under the experimental conditions is not noted. Phenylglyoxal is regarded as one of the intermediates of phenylacetylene autoxidation. The formation of benzoic acid in all cases and considerable amounts of benzil from 1-phenyl-propane-1,2-dione and 1-phenyl-butane-1,2-dione in the thermal decomposition at 130° in presence of dibenzoyl peroxide, diacetyl peroxide or di-tert-butyl peroxide using chlorohenzene as solvent show that the reactions of the type Ph-CO-CO-R + X_ → Ph-CO_ + R-CO-X (with X_ = R'-O_ or R'-CO-O_) take place during the course of autoxidation of α-diketones. The products expected from the reaction of the short lived intermediate ketocarbenes with oxygen i.e. α-dicarbonyl compounds and lower carboxylic acids, especially benzoic acid were not detected in the thermal and photochemical decomposition of α-diazoacetophcnone, α-diazopropiophenone, α-diazobutyrophenone and a-diazodesoxyhenzoin. This shows that the oxidative scission of the C≡C bond proceeds via the corresponding α-dicarbonyl compounds as intermediates and not via the corresponding oxirenes or the valence isomeric ketocarbenes.

Structural analysis of pyrrolidinones.

In the course of a study on pyrrolidinones, the crystal structures of four compounds, namely, methyl N-[(4-meth­oxy­phenyl)(3,4,5-tri­meth­oxy­phenyl)­methyl]­pyro­glut­amate, C23­H27­NO7, methyl N-[naphthyl-(3,4,5-tri­meth­oxy­phenyl)­methyl]­pyro­glut­amate diacetyl peroxide, C26­H27­NO6·-0.5C4H6O4, 5-(3,4,5-tri­meth­oxy­phenyl)-1,2,3,11b-tetrahy­dro-5H-naphtho­[1,8-f,g]indol­izin-3-one, C24­H23­NO4, and 5-(3,4,5-tri­meth­oxy­phenyl)-1,2,3,5,12,12a-hexa­hydro­naph­tho­[1,2-f]indol­izine-3,12-dione, C25­H23­NO5, are presented, compared and discussed.

Thermochemical kinetics of bromine nitrate, bromine nitrite, halogen hydroperoxides, dichlorine pentoxide, peroxycarboxylic acids, and diacyl peroxides

Heats of formation of BrONO_2, BrONO, BrOOH, FOOH, FOOCl, CF_3C(O)OOH, HC(O)OOH, CH_3C(O)OOH, and [CH_3C(O)O]_2 are estimated from bond contributions taken from J. Phys. Chem.,100, 10150 (1996). They agree within ±2 kcal/mol with recent experimental or ab initio data. The resulting BDE(O-O) = 36 kcal/mol value in diacetyl peroxide requires the concerted assistance of exothermic C-C(O) weakening in the transition state of its decomposition into free radicals. It also implies the existence of a previously unrecognized 12 kcal/mol nonbonded repulsion in acyl anhydrides. The formation of chloryl chlorate with ΔH_f(O_2ClOClO_2) = 50 kcal/mol, a marginally stable species toward dissociation into (ClO_3+OClO), may account for observations made in the [O(^3P+OClO] system at low temperatures.

A Reassessment of the Bond Dissociation Energies of Peroxides. An ab Initio Study

The strength of the O−O bond is of fundamental importance in a variety of chemical processes. Traditionally, a value of 34 kcal/mol has been ascribed to a generic O−O bond dissociation energy. The present, high-level ab initio calculations indicate that the average O−O bond energy is significantly higher, ca. 45 kcal/mol, and that the bond energy is sensitive to the bonding environment. Calculations at the G2 level of theory give bond dissociation enthalpies at 298 K of 50 kcal/mol for HOOH, 45 kcal/mol for CH3OOH, 39 kcal/mol for CH3OOCH3, and 48 kcal/mol for HC(O)OOH and CH3C(O)OOH. The G2(MP2) results are similar and, additionally, give bond dissociation enthalpies of 38 kcal/mol for diacetyl peroxide, 49 kcal/mol for trifluoroperoxyacetic acid, 23 kcal/mol for isopropenyl hydroperoxide, and 22 kcal/mol for peroxynitrous acid.

ChemInform Abstract: Kinetics of the Perhydrolysis of p‐Nitrophenyl Acetate and the Formation, Hydrolysis, and Perhydrolysis of Diacetyl Peroxide.

AbstractReactions of the model bleach activator p‐nitrophenyl acetate with H2O2 in aqueous carbonate, borate, and phosphate buffers are investigated.

Studies on the oxidative cleavage of the CC triple bond during the autoxidation of acetylenic hydrocarbons. IV. The reaction of Acyloxy and Alkoxy Radicals with α‐diketones

AbstractDibenzoyl peroxide, diacetyl peroxide and di‐tert‐butyl peroxide were thermally decomposed at 130°C in the presence of benzil, 1‐phenyl‐propane‐1,2‐dione, and 1‐phenyl‐butane‐1,2‐dione using chlorobenzene as the solvent. In all cases benzoic acid was formed. Moreover, from 1‐phenyl‐propane‐1,2‐dione and 1‐phenylbutane‐1,2 dione considerable amounts of benzil were obtained. The results show that reactions of the type equation image (with X· R′O· or X· R′COO·), previously formulated by us to explain the course of the autoxidation of α‐diketones, really take place.

MNDO analysis of aliphatic diacyl peroxide conformation

We have examined the molecular geometry of the last by SCF MO LCAO in the MNDO approximation [3] for diacetyl peroxide (I), acetyl propionyl peroxide (II), and acetyl-2-methyl propionyl peroxide (III). In calculations on I, the bond lengths and angles were taken as identical in accordance with the C 2 symmetry. The rotations around the C-O bonds were taken as independent. For III, it was assumed that the CH 3 groups retain their tetrahedral structure. The geometrical parameters for both such groups in the hemmethyl moiety were taken as identical. In the optimization of II, no assumptions were made about symmetry retention in any of the~parts. The calculations were compared with measurements via ones on the geometry on acetyl benzoyl peroxide (IV). A planar structure was assumed for the phenyl moiety, while all the other parameters were taken as independent.

Synthesis and Thermal Decomposition of Di-t-Butyl Peroxydicarbonate

Abstract Di-t-butyl peroxydicarbonate(DBPD) has been synthesized in a novel route and thermally decomposed at 40–70 °C. The decomposition exhibits first-order kinetics and the values of ΔH\eweq and ΔS\eweq are 122 kJ mol−1 and 46 J K−1 mol−1, respectively. 2-Methyl-2-propanol is obtained quantitatively as a decomposition product and the rates are a little dependant on the viscosities of solvents, normal alkanes. The mechanism that involves the initial scission of the O–O bond is discussed and the values of the rates and the activation parameters of DBPD are compared with those of diacetyl peroxide and dibenzoyl peroxide.

Abfangreaktionen kurzlebiger radikale XVIII. Kinetische und CIDNP-studien der photoreaktion von distannanen mit alkylhalogeniden und der thermischen reaktion mit diacylperoxiden

A longlived triplet state is shown by 119Sn CIDNP for distannanes R 6Sn 2 upon irradiation ( E T = 300 kJ), which may be split into 2 radicals R 3Sn·( k a), but also into R 5Sn 2· + R· ( k b. With R = Me, k a is more important, but with R = Et, Bu, k a ≈ k b. Compounds R 6Sn 2 are cleaved by R· into R 4Sn + R 3Sn·, the effectivity being increased in the series t-Bu < i-Pr << Pr < Et < Me ≈ Ph. For Me 6Sn 2 and Me·, k = 0.85 X 10 4 l mol −1 sec −1 at 23°C. The distannane Et 5Sn 2Br is attacked by Me· predominantly, by Pr· and Bu· exclusively at the halogenated Sn atom. Diacetyl peroxide reacts quickly with R 6Sn 2 via a nonradical mechanism yielding MeCOOSnR 3, as does dibenzoyl peroxide analogously but more slowly. In both cases a free-radical reaction is superposed ( 13C CIDNP) giving R 4Sn, CO 2, and RCOOSnR 3. It is stopped by t-BuBr, but increased markedly at higher temperatures.

Calculation of the normal vibrations and characteristics of the infrared spectrum of diacetyl peroxide

Calculation of the normal vibrations and characteristics of the infrared spectrum of diacetyl peroxide

Chemical alteration of nucleic acids and their components—XIII: Reaction of nucleosides with diacyl peroxides

Diacyl peroxides reacted at room tempt with cytidine and adenosine. The former gave 4-acyl and 3-oxido derivatives and the latter gave 6-acyl and 1-oxido derivatives. At 90°, diacetyl peroxide reacted with guanosine, adenosine, cytidine, and uridine by a homolytic process to give their C-methylated derivatives. The latter reaction was accelerated by the presence of a ferrous ion.

Reaction of diacetyl peroxide with phenyl alkyl ketones. Reexamination

Reaction of diacetyl peroxide with phenyl alkyl ketones. Reexamination

The free‐radical reaction of tri‐n‐butyltin hydride with peroxides

AbstractRate constants for the tri‐n‐butyltin radical (Sn ·) induced decomposition of a number of peroxides have been measured in benzene at 10°C. The values range from ∼100 M−1 sec−1 for di‐t‐butyl peroxide to 2.6 × 107 M−1 sec−1 for di‐t‐butyl diperoxyisophthalate. The majority of the peroxides, including diethyl peroxide, diacetyl peroxide, and t‐butyl peracetate, have rate constants of ∼105 M−1 sec−1. It is shown that di‐n‐alkyl disulfides are ten times as reactive toward Sn · as di‐n‐alkyl peroxides, although the exothermicities of these reactions are ∼15 and ∼39 kcal/mole, respectively. The enhanced reactivity of the disulfides is attributed to the easier formation of an intermediate or transition state with 9 electrons around sulfur, compared with an analogous species with 9 electrons around oxygen.The following bond strengths (kcal/mole) have been estimated: D[SnOR] = 77; D[SnH] = 82; D[SnSR] = 83; and D[SnOC(O)R] = 86, where R = alkyl. Rate constants for reaction of Sn · with some benzyl esters have also been measured. It has been found that t‐butoxy radicals can add to benzene and abstract hydrogen from benzene at ambient temperatures.

A gas chromatographic method for isolation and determination of diacetyl peroxide

A gas chromatographic method for isolation and determination of diacetyl peroxide

Correction- Improved Yields in the Preparation of Diacetyl Peroxide.

Correction- Improved Yields in the Preparation of Diacetyl Peroxide.

Reactions of Methyl and Ethoxy Free Radicals in Chlorohydrocarbons: A Comparative Study of the Use of Diacetyl Peroxide and Diethylperoxydicarbonate as Agents for Linking Alpha Carbon to Alpha Carbon in Some Chloro-Substituted Aralkyls1

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReactions of Methyl and Ethoxy Free Radicals in Chlorohydrocarbons: A Comparative Study of the Use of Diacetyl Peroxide and Diethylperoxydicarbonate as Agents for Linking Alpha Carbon to Alpha Carbon in Some Chloro-Substituted Aralkyls1HENRY C. McBAY, OZIE TUCKER, and PAUL T. GROVESCite this: J. Org. Chem. 1959, 24, 4, 536–545Publication Date (Print):April 1, 1959Publication History Published online1 May 2002Published inissue 1 April 1959https://doi.org/10.1021/jo01086a024RIGHTS & PERMISSIONSArticle Views124Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts