65842-25-3Relevant articles and documents
Extreme rate acceleration by axial thiolate coordination on the isomerization of endoperoxide catalyzed by iron porphyrin
Yamane, Takehiro,Makino, Kohei,Umezawa, Naoki,Kato, Nobuki,Higuchi, Tsunehiko
supporting information; experimental part, p. 6438 - 6440 (2009/03/11)
(Chemical Equation Presented) A coordinated effort: The isomerization mechanism of prostaglandin H2 (PGH2), which is catalytically isomerized to prostacyclin or thromboxane A2 by cytochrome P450s, was investigated using a hemethiolate complex and an endoperoxide. Isomerization of endoperoxides proceeded very rapidly with this complex, whereas imidazole- or chloride-ligated heme had slight or no catalytic activity (see scheme).
Ruthenium(II)-Catalyzed Reactions of 1,4-Epiperoxides
Suzuki, Masaaki,Ohtake, Hiroaki,Kameya, Yoshimi,Hamanaka, Nobuyuki,Noyori, Ryoji
, p. 5292 - 5302 (2007/10/02)
The behavior of 1,4-epiperoxides in the presence of transition-metal complexes is highly dependent on the structures of the substrates and the nature of the metal catalysts.Reaction of saturated epiperoxides such as 1,3-epiperoxycyclopentane, 1,4-epiperoxycyclohexane, or dihydroascaridole catalyzed by RuCl2(PPh3)3 in dichloromethane gives a mixture of products arising from fragmentation, rearrangement, reduction, disproportionation, etc.Prostaglandin H2 methyl ester undergoes clean and stereospecific fragmentation to afford methyl(5Z,8E,10E,12S)-12-hydroxy-5,8,10-heptadecatrienoate and malonaldehyde.Bicyclic 2,3-didehydro 1,4-epiperoxides give the syn-1,2:3,4-diepoxides by the same catalyst.The monocyclic analogues are transformed to a mixture of diepoxides and furan products.The stereochemical outcome of the epoxide formation reflects unique differences in the ground-state geometry of the starting epiperoxide substrates.FeCl2(PPh3)2 serves as a useful catalyst for the skeletal change of sterically hindered bicyclic 2,3-didehydro 1,4-epiperoxides to the syn-diepoxides.In addition, the Fe complex best effects the conversion of 1,4-unsubstituted 2,3-didehydro epiperoxides to furans.The Ru-catalyzed reactions are interpreted in terms of the intermediacy of inner-sphere radicals formed by atom transfer of the Ru(II) species to peroxy substrates, in contrast to the Fe-catalyzed reactions proceeding via free, outer-sphere radicals generated by an electron-transfer mechanism.
PHOTOLYSIS OF SATURATED BICYCLIC PEROXIDES
Bloodworth, A.J.,Eggelte, Henny J.
, p. 1525 - 1528 (2007/10/02)
Under direct photolysis (n.2.1)-peroxides (n=3-5) isomerise chiefly to epoxyaldehydes, (n.2.2)-peroxides (n=2-4) mainly undergo dehydrogenation to cycloalkane-1,4-diones, and 2,3-dioxabicyclo(2.2.1)heptane exhibits both types of behaviour; photo-isomerisation of 6,7- into 6,8-dioxabicyclooctane occurs when benzophenone is present as sensitiser.
