An In‐Depth Look at the Reactivity of Non‐Redox‐Metal Alkylperoxides

• Published in: Angewandte Chemie International Edition Vol. 58; no. 25; pp. 8526 - 8530
• Main Authors: Pietrzak, Tomasz, Justyniak, Iwona, Kubisiak, Marcin, Bojarski, Emil, Lewiński, Janusz
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 17-06-2019
• Edition: International ed. in English
• Subjects: Alkyl compounds; alkyls; Base metal; Coordination compounds; dioxygen; Ligands; Metal hydroxides; Metals; Organometallic compounds; Oxidation; Oxygen transfer; Oxygenation; peroxide; Zinc; peroxide; alkyls; oxygenation; dioxygen; zinc
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201904380

Over the past 150 years, a certain mythology has arisen around the mechanistic pathways of the oxygenation of organometallics with non‐redox‐active metal centers as well as the character of products formed. Notably, there is a widespread perception that the formation of commonly encountered metal alkoxide species results from the auto‐oxidation reaction, in which a parent metal alkyl compound is oxidized by the metal alkylperoxide via oxygen transfer reaction. Now, harnessing a well‐defined zinc ethylperoxide incorporating a β‐diketiminate ligand, the investigated alkylperoxide compounds do not react with the parent metal alkyl complex as well as Et2Zn to form a zinc alkoxide. Upon treatment of the zinc ethylperoxide with Et2Zn, a previously unobserved ligand exchange process is favored. Isolation of a zinc hydroxide carboxylate as a product of decomposition of the parent zinc ethylperoxide demonstrates the susceptibility of the latter to O−O bond homolysis.
Despite the oxidizing properties of zinc alkylperoxides, these species react neither with the parent zinc alkyl complex, nor with the homoleptic ethylzinc compound with the formation of zinc alkoxides. Moreover, the isolation of a zinc hydroxide acetate as a product of the transformation of the parent zinc ethylperoxide demonstrates pronounced susceptibility of the latter to the O−O bond homolysis.