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

Abstract

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 Et₂ Zn to form a zinc alkoxide. Upon treatment of the zinc ethylperoxide with Et₂ Zn, 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.

Keywords: alkyls; dioxygen; oxygenation; peroxide; zinc.