Kinetic Study of the Oxygenation of 2,5-Dimethylpyrrole. A Model Compound Study Designed To Probe Initiation of the Oxidative Degradation of Petroleum Products

Insight into the Mechanisms of Middle Distillate Fuel Oxidative Degradation. Part 2: On the Relationship between Jet Fuel Thermal Oxidative Deposit, Soluble Macromolecular Oxidatively Reactive Species, and Smoke Point

“…We have previously proposed that electron-rich aromatic molecules such as pyrroles, 11,12 indoles, 13 and carbazoles can be thermally promoted to react directly with molecular oxygen. [14][15][16] It is conceivable that such chemistry could ultimately lead to production of a high concentration of peroxyl radicals.…”

An unusual thermal oxidation of triaryloxazoles

“…Other examples include oxidation of retinoic acid under high O 2 pressure, 12 an endoperoxide from a germanium derivative of naphthoquinone, 13 oxidation of 9,10-dibenzoylphenanthrene, 14 and oxidation of 2,5-dimethylpyrrole. 15 In all these cases, the authors postulate a relatively facile and reversible addition of oxygen to an unsaturation or aromatic ring to give a triplet diradical. Sometimes the spin inversion apparently occurred spontaneously, although slowly, while in other cases oneelectron catalysts or heavy atoms accelerated the inversion.…”

Structural effects on the reactivity of substituted arylphosphines as potential oxygen-scavenging additives for future jet fuels

“…We define the most simple case of ETIO as an oxygenation reaction in which the rate-limiting step involves an electron transfer from the substrate to molecular oxygen (or an activated form of oxygen). We have postulated that electron-rich molecules that have low oxidation potentials, such as various triarylphosphines [7], can be induced to undergo ETIO reactions [8]. Scheme 1 depicts our recent ETIO mechanistic proposal for the reaction of aryl phosphines at 150ЊC in oxygen-saturated dodecane in the presence of a phenolic antioxidant (BHT) [5].…”