TY - JOUR
T1 - Metal-peroxo versus metal-oxo oxidants in non-heme iron-catalyzed olefin oxidations
T2 - Computational and experimental studies on the effect of water
AU - Quiñonero, David
AU - Morokuma, Keiji
AU - Musaev, Djamaladdin G.
AU - Mas-Ballesté, Rubén
AU - Que, Lawrence
PY - 2005/5/11
Y1 - 2005/5/11
N2 - Computational and experimental studies show that Fe(BPMEN)-catalyzed olefin oxidation has two (FeIII-OOH and FeV=O) oxidant species, which act with comparable activation barriers. The presence of water favors formation of an HO-FeV=O oxidant via water-assisted O-OH bond cleavage and leads to both epoxide and cis-diol products. In the absence of water, the oxidant is the FeIII-OOH [or (MeCN)FeIII-OOH], and oxidation mainly leads to epoxide. This conclusion differs from that derived from DFT investigations of iron-porphyrin-catalyzed olefin epoxidation, where the FeIII-OOH pathway is deemed too high in energy to be plausible. The difference between these two systems may lie in the more flexible coordination environment of the non-heme iron complex, which has an available adjacent coordination site that contributes to the activation of the peroxide in both wa and nwa pathways.
AB - Computational and experimental studies show that Fe(BPMEN)-catalyzed olefin oxidation has two (FeIII-OOH and FeV=O) oxidant species, which act with comparable activation barriers. The presence of water favors formation of an HO-FeV=O oxidant via water-assisted O-OH bond cleavage and leads to both epoxide and cis-diol products. In the absence of water, the oxidant is the FeIII-OOH [or (MeCN)FeIII-OOH], and oxidation mainly leads to epoxide. This conclusion differs from that derived from DFT investigations of iron-porphyrin-catalyzed olefin epoxidation, where the FeIII-OOH pathway is deemed too high in energy to be plausible. The difference between these two systems may lie in the more flexible coordination environment of the non-heme iron complex, which has an available adjacent coordination site that contributes to the activation of the peroxide in both wa and nwa pathways.
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U2 - 10.1021/ja051062y
DO - 10.1021/ja051062y
M3 - Article
C2 - 15869272
AN - SCOPUS:18644383025
SN - 0002-7863
VL - 127
SP - 6548
EP - 6549
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 18
ER -