Inspired by the versatile oxidation chemistry catalyzed by nonheme iron enzymes, we have been exploring the chemistry of hydrocarbon oxidations catalyzed by nonheme iron complexes of neutral tetradentate ligands employing H2O2 as oxidant in the presence of acetic acid (AcOH).1 While reactions conducted in the absence of AcOH generally give rise to iron(III)-hydroperoxo intermediates that undergo rate determining O–O bond cleavage to unmask an FeV(O)(OH) oxidant,2 the introduction of AcOH leads to the accumulation of an iron(III)-acylperoxo intermediate that can be characterized spectroscopically.1 DFT calculations of Wang and Shaik raise the possibility that such species may exist in equilibrium with O−O bond cleaved electromers, FeIV(O)(OAc●) and FeV(O)(OAc),1,3 that may participate in the observed oxidative transformations. Experimental results that provide support for these mechanistic notions will be discussed. References 1. Oloo, W. N.; Meier, K. K.; Wang, Y.; Shaik, S.; Münck, E.; Que, L., Jr., Identification of a Low-spin Acylperoxoiron(III) Intermediate in Bio-inspired Nonheme Iron-Catalyzed Oxidations Nature Communications 2014, DOI: 10.1038/ncomms4046. 2. Oloo, W. N.; Fielding, A. J.; Que, L., Jr., Rate Determining Water-Assisted O–O Bond Cleavage of a FeIII–OOH Intermediate in a Bio-inspired Nonheme Iron-Catalyzed Oxidation J. Am. Chem. Soc. 2013, 135, 6438-6441. 3. Wang, Y.; Janardanan, D.; Usharani, D.; Han, K.; Que, L., Jr.; Shaik, S. The Nonheme Iron Oxidant Formed in the Presence of H2O2 and Acetic Acid Is the Cyclic Ferric-peracetate Complex and Not a Perferryl-oxo Complex. ACS Catal. 2013, 3, 1334-1341.

Intermediates in hydrocarbon oxidations catalyzed by bio-inspired nonheme iron catalysts

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.