Liquid-phase Oxidation of Aldehydes

Highly Efficient Organic Reactions “on Water”, “in Water”, and Both

“…The oxidation of aldehydes by oxygen or oxygen/nitrogen mixtures is a well-known reaction. [5] Organic chemistry textbooks pay very little attention to the use of air in the synthesis of carboxylic acids from aldehydes. Notably, air is the ultimate "green" oxidant, more so than hydrogen peroxide, which is considered "green" for synthetic oxidation processes.…”

“…Two possible pathways may account for this labeling: either rapid aldehyde/gem-diol equilibration [20] on the water surface or an exchange reaction in one of the peroxo or radical species that are postulated in the oxidation of aldehydes by molecular oxygen (Scheme 3). [5] Interestingly, when the Passerini reaction (Scheme 2) was performed in H 2 18 O, the incorporation of Scheme 2. Tandem aldehyde oxidation/Passerini reaction "on water".…”

On the mechanism of erythrocyte hemolysis induced by photooxidized psoralen

“…Furthermore, formation and accumulation of hydrogen peroxide (H 2 O 2 ) proceeds in POP solutions, with H 2 O 2 being accumulated in solutions even after the end of irradiation, which may result from the autooxidation of aldehydic photoproducts of psoralen [36]. Aldehydic photoproducts absorb UV A radiation, which may trigger autooxidation, with further processes progressing like a chain reaction [16,36].…”

Design, Synthese und In-situ-Charakterisierung neuer Feststoffkatalysatoren

“…[203,204] welche über die in Schema 2 angegebene Reaktionsfolge zur Bildung von Benzoesäure und Cyclohexenoxid führen. Bei dieser Sequenz weiû man, [205,206] daû der fünfte Teilschritt viel schneller abläuft als der sechste. Diese auf freien Radikalen basierende Epoxidierung von Cyclohexen (und den anderen Alkenen in Tabelle 6) ist mechanistisch sehr verschieden von der radikalfreien Epoxidierung von Alkenen unter Verwendung von Alkylhydroperoxiden und Titanosilicat-Katalysatoren (die in Abschnitt 7.4.2 diskutiert wird).…”