TY - JOUR
T1 - Catalytic oxidative ring opening of THF promoted by a carboxylate-bridged diiron complex, triarylphosphines, and dioxygen
AU - Moreira, Rayane F.
AU - Tshuva, Edit Y.
AU - Lippard, Stephen J.
PY - 2004/7/12
Y1 - 2004/7/12
N2 - The catalytic oxidation of triphenylphosphine in the presence of dioxygen by the diiron(II) complex [Fe2(μ-O2- CAr Tol)2(Me3TACN)2(MeCN) 2](OTf)2 (1), where -O2CAr Tol = 2,6-di(p-tolyl)benzoate and Me3TACN = 1,4,7-trimethyl-1,4,7-triazacyclononane, has been investigated. The corresponding diiron(III) complex, [Fe2(μ-O)(μ-O 2CArTol)2(Me3-TACN) 2](OTf)2 (2), the only detectable iron-containing species during the course of the reaction, can itself promote the reaction. Phosphine oxidation is coupled to the catalytic oxidation of THF solvent to afford, selectively, the C-C bond-cleavage product 3-hydroxypropylformate, an unprecedented transformation. After consumption of the phosphine, solvent oxidation continues but results in the products 2-hydroperoxytetrahydrofuran, butyrolactone, and butyrolactol. The similarities of the reaction pathways observed in the presence and absence of catalyst, as well as 18O labeling, solvent dependence, and radical probe experiments, provide evidence that the oxidation is initiated by a metal-centered H-atom abstraction from THF. A mechanism for catalysis is proposed that accounts for the coupled oxidation of the phosphine and the THF ring-opening reaction.
AB - The catalytic oxidation of triphenylphosphine in the presence of dioxygen by the diiron(II) complex [Fe2(μ-O2- CAr Tol)2(Me3TACN)2(MeCN) 2](OTf)2 (1), where -O2CAr Tol = 2,6-di(p-tolyl)benzoate and Me3TACN = 1,4,7-trimethyl-1,4,7-triazacyclononane, has been investigated. The corresponding diiron(III) complex, [Fe2(μ-O)(μ-O 2CArTol)2(Me3-TACN) 2](OTf)2 (2), the only detectable iron-containing species during the course of the reaction, can itself promote the reaction. Phosphine oxidation is coupled to the catalytic oxidation of THF solvent to afford, selectively, the C-C bond-cleavage product 3-hydroxypropylformate, an unprecedented transformation. After consumption of the phosphine, solvent oxidation continues but results in the products 2-hydroperoxytetrahydrofuran, butyrolactone, and butyrolactol. The similarities of the reaction pathways observed in the presence and absence of catalyst, as well as 18O labeling, solvent dependence, and radical probe experiments, provide evidence that the oxidation is initiated by a metal-centered H-atom abstraction from THF. A mechanism for catalysis is proposed that accounts for the coupled oxidation of the phosphine and the THF ring-opening reaction.
UR - http://www.scopus.com/inward/record.url?scp=3142658788&partnerID=8YFLogxK
U2 - 10.1021/ic049460+
DO - 10.1021/ic049460+
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
C2 - 15236556
AN - SCOPUS:3142658788
SN - 0020-1669
VL - 43
SP - 4427
EP - 4434
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 14
ER -