79171-56-5Relevant academic research and scientific papers
Ruthenium(II)-Catalyzed Reactions of 1,4-Epiperoxides
Suzuki, Masaaki,Ohtake, Hiroaki,Kameya, Yoshimi,Hamanaka, Nobuyuki,Noyori, Ryoji
, p. 5292 - 5302 (1989)
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.
PALLADIUM(0) CATALYZED REACTIONS OF 1,4-EPIPEROXIDES
Suzuki, Masaaki,Oda, Yoshihisa,Hamanaka, Nobuyuki,Noyori, Ryoji
, p. 517 - 535 (2007/10/02)
The Pd(PPh3)4 catalyzed reaction of 2,3-saturated and 2,3-unsaturated 1,4-epiperoxides proceeds by courses markedly different from those of the previously reported transition metal catalyses.The Pd(0)-promoted reaction of 2,3-saturated epiperoxides gives the corresponding 4-hydroxy ketones and 1,4-diols as the major products.From 2,3-dedihydroepiperoxides are formed the corresponding 4-hydroxy enones, syn-1,2;3,4-diepoxides, and 1,4-diols.The results are interpreted in terms of competing Pd(0)/Pd(II) exchange mechanisms.Exposure of prostaglandin (PG) H2 methyl esterto Pd(PPh3)4 produces a mixture of methyl esters of PGD2, PGE2, PGF2α, and (5Z,8E,10E,12S)-12-hydroxy-5,8,10-heptadecatrienoic acid.
