- Cis-Trans Isomerization of Epoxides Catalyzed by Ruthenium(II) Porphyrins
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Bis(tetrahydrofuran)(5,10,15,20-tetramesyitylporphyrinato)ruthenium(II) IITMP(THF)2> and the corresponding p-tolylporphyrin IITTP(THF)2> have been found to catalyze the cis-trans isomerization of epoxides under mild conditions.For β-methylstyrene oxide an equilibrium ratio of 5.4:1 (trans/cis) was achieved with either isomer indicating a free energy difference of 1 kcal/mol.Inhibition of the isomerization by added olefins was observed and attributed to olefin coordination to ruthenium(II). cis-β-Methylstyrene oxide readily formed an adduct with RuIITMP(CO), while the trans isomer did not.The isomerization of trans-(1S,2S)-β-methylstyrene oxide gave only cis-(1R,2S)β-methylstyrene oxide.A mechanism for epoxide isomerization involving homolytic cleavage of the C1-O bond to give carbon radical intermediate is proposed.
- Groves, John T.,Ahn, Kwang-Hyun,Quinn, Robert
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p. 4217 - 4220
(2007/10/02)
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- Synthesis and Reactivity of a Monomeric 14-Electron 'Bare' Ruthenium(II) Porphyrin Complex; Reversible Binding of Dinitrogen to form Mono- and Bis-dinitrogen Complexes
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The 14-electron species Ru(TMP), obtained via vacuum pyrolysis of Ru(TMP)(MeCN)2, reacts with a plethora of ligands to form bis-ligated species, including the first bis(dinitrogen) metalloporphyrin complex .
- Camenzind, Mark J.,James, Brian R.,Dolphin, David
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p. 1137 - 1139
(2007/10/02)
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