title: Nucleophilic reactivity of a copper(II)-superoxide complex.
abstract: Metal-bound superoxide intermediates are often implicated as electrophilic oxidants in dioxygen-activating metalloenzymes. In the nonheme iron α-ketoglutarate dependent oxygenases and pterin-dependent hydroxylases, however, Fe(III)-superoxide intermediates are postulated to react by nucleophilic attack on electrophilic carbon atoms. By reacting a Cu(II)-superoxide complex (1) with acyl chloride substrates, we have found that a metal-superoxide complex can be a very reactive nucleophile. Furthermore, 1 was found to be an efficient nucleophilic deformylating reagent, capable of Baeyer-Villiger oxidation of a number of aldehyde substrates. The observed nucleophilic chemistry represents a new domain for metal-superoxide reactivity. Our observations provide support for the postulated role of metal-superoxide intermediates in nonheme iron α-ketoglutarate dependent and pterin-dependent enzymes.
authors.affiliation: School of Chemistry and CRANN/AMBER Nanoscience Institute, Trinity College Dublin, College Green, Dublin 2 (Ireland) http://www.tcd.ie/Chemistry/staff/people/mcdonald/
authors.forename: Paolo
authors.initials: P
authors.lastname: Pirovano
authors.forename: Adriana M
authors.initials: AM
authors.lastname: Magherusan
authors.forename: Ciara
authors.initials: C
authors.lastname: McGlynn
authors.forename: Andrew
authors.initials: A
authors.lastname: Ure
authors.forename: Amy
authors.initials: A
authors.lastname: Lynes
authors.forename: Aidan R
authors.initials: AR
authors.lastname: McDonald
mesh_terms: D003300:Copper / Q000737:chemistry*; D010084:Oxidation-Reduction; D013481:Superoxides
chemical_list: D013481:Superoxides; D003300:Copper
keywords: bioinorganic chemistry; dioxygen activation; nucleophilic reactivity; reaction mechanisms; superoxide complexes