DUGi

Reactivity of a Nickel(II) Bis(amidate) Complex with meta-Chloroperbenzoic Acid: Formation of a Potent Oxidizing Species

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@10256@@13280

Herein, we report the formation of a highly reactive nickel-oxygen species that has been trapped following reaction of a NiII precursor bearing a macrocyclic bis(amidate) ligand with meta-chloroperbenzoic acid (HmCPBA). This compound is only detectable at temperatures below 250 K and is much more reactive toward organic substrates (i.e., CH bonds, CC bonds, and sulfides) than previously reported well-defined nickel-oxygen species. Remarkably, this species is formed by heterolytic OO bond cleavage of a Ni-HmCPBA precursor, which is concluded from experimental and computational data. On the basis of spectroscopy and DFT calculations, this reactive species is proposed to be a NiIII-oxyl compound. A highly reactive nickel-oxygen species has been spectroscopically trapped after heterolytic OO bond cleavage during the reaction of a NiII precursor with meta-chloroperbenzoic acid (HmCPBA). This species is used to carry out the oxidation of different substrates, such as olefins, sulfides, and CH bonds (see scheme)

Financial support for this work was provided by the European Commission (FP7-PEOPLE-2011-CIG-303522 to A.C.) and the COST Action CM1305 (ECOSTBio) including a STSM grant (COST-STSM-CM1305-21541) to T.C. The Spanish Ministry of Science is acknowledged for a Ramûn y Cajal contract to A.C. Also F.A.-P. thanks the Universitat de Girona for a predoctoral grant. K.R. thanks the Cluster of Excellence “Unifying Concepts in Catalysis” (EXC 314/2), Berlin and the Heisenberg Programme of the Deutsche Forschungsgemeinschaft for financial support. J.L.-F. thanks the Cellex Foundation for financial support from the starting-career program. W.R.B. acknowledges the European Research Council (ERC-2011-StG-279549) and the Ministry of Education, Culture and Science (Gravity program 024.001.035 to A.D. and W.R.B.)

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