ChemInform Abstract: Rose Bengal Functionalized Phase-Transfer Catalysts Promoting Photooxidations with Singlet Oxygen. Nucleophilic Displacements on Dioxetanic and Endoperoxide Intermediates.
Abstract
Rose bengal-promoted photooxidation of 5,6-dihydro-2,3-diphenyl-p-dioxin (I) in a two-phase system in the presence of a phosphonium salt as the phase-transfer catalyst yields a mixture of the dioxetane (II) and the diester (III).
ChemInform Abstract
Rose bengal-promoted photooxidation of 5,6-dihydro-2,3-diphenyl-p-dioxin (I) in a two-phase system in the presence of a phosphonium salt as the phase-transfer catalyst yields a mixture of the dioxetane (II) and the diester (III). Thermolysis of (II) gives the rearrangement product (III). The hydroxy azide (IV) is obtained on photooxidation of (I) in the presence of sodium azide. Anthracene (V), indene (VI), 1,3-cyclohexadiene (VII), and 2,3-dimethyl-2-butene (VIII) also undergo singlet- oxygenation under analogous conditions. Some onium salts of rose bengal immobilized on silica gel are also used as catalysts.
