Oxygenation of a Me₂Zn/α‐Diimine System: A Unique Zinc Methylperoxide Cluster and Evidence for Its Sequential Decomposition Pathways

Abstract

O, was für eine Reaktion: Die Oxygenierung von Me2Zn⋅tBu‐DAB (tBu‐DAB= 1,4‐Di‐tert‐butyl‐1,4‐diazabutadien) liefert das neuartige Oxo(methylperoxid)‐Cuban 1, das entsprechende doppelt cubische Oxo(methoxid) 2 und das C‐C‐verknüpfte zweikernige Methoxid [(MeZn)2(tBu‐DAB‐DAB(H)‐tBu)(μ‐OMe)], dessen Bildung mit der Homolyse einer ZnO‐OMe‐Bindung beginnt.

Transformation of Ethylzinc Species to Zinc Acetate Mediated by O2 Activation: Reactive Oxygen‐Centered Radicals Under Control

“…The generation of zinc oxyl and alkoxy radicals from homolysis of the ZnOOR bond have been well‐documented in our previous studies; however the nascent RO . radicals have always diffused out of the cage 4l,m. 5 We suggest that in the present case, the putative capsule suppresses the escape of EtO .…”

“…Metal alkyl peroxide complexes have been proposed as intermediates in these reactions,3, 4 and the formation of the most commonly observable alkoxides as final products has traditionally been explained by σ bond metathesis involving an alkyl peroxide intermediate and the starting metal alkyl complex 2. 4a Our recent systematic investigations have not only advanced a plausible hypothesis concerning the mechanism of O 2 activation by organometallic compounds,4b,c,k,l, 5 but also convincingly demonstrated a high tendency of incipient zinc peroxide species to form relatively stable adducts with the parent zinc alkyl complex 4m. 5 Moreover, we have revealed a long overlooked decomposition pathway of zinc alkyl peroxides via homolysis of the OO bond, which is responsible for the formation of oxo complexes 4l,m.…”

“…4a Our recent systematic investigations have not only advanced a plausible hypothesis concerning the mechanism of O 2 activation by organometallic compounds,4b,c,k,l, 5 but also convincingly demonstrated a high tendency of incipient zinc peroxide species to form relatively stable adducts with the parent zinc alkyl complex 4m. 5 Moreover, we have revealed a long overlooked decomposition pathway of zinc alkyl peroxides via homolysis of the OO bond, which is responsible for the formation of oxo complexes 4l,m. 5 To date, the formation of alkyl peroxide (path a, Scheme ), alkoxide (path b), and oxo species (path c) in the oxygenation of ZnR species has been well‐documented.…”

Probing the Role of π Interactions in the Reactivity of Oxygen Species: A Case of Ethylzinc Aryloxides with Different Dispositions of Aromatic Rings toward the Metal Center

“…The oxygenation of 3 to 7 demonstrates for the first time that the formation of hydroxide species occurs and substantiates the transformation of dioxygen into a peroxo anion in the O 2 activation processes mediated by alkylzinc compounds (Scheme , paths e and f). The formation of alkylperoxide,9c–f,h, 10b alkoxide,9d–f,j, 10 oxo,9g,h,j and even carboxylate species9i in the oxygenation of ZnR units has been well documented (Scheme , paths a–d). Finally, the new reaction outcomes clearly indicate that the outlined approach, which involves the suitable positioning of aromatic functionalities near the metal center, may be useful as a model system for the examination of transformations that involve either O 2 and ROS and mediation by means of organometallic compounds and various bioinorganic oxygenation systems.…”

Unveiling Complexity of the Oxygenation of Aluminum Alkyls by the Isolation of Unique Alkylperoxide and Oxoalkoxide Compounds

“… 11 , 27 , 28 Moreover, considering the chemistry of NR MOOR species, particular mention should be made of the O–O bond scissions. Although regularly overlooked, homolysis of the O–O bond appears to be the critical factor responsible for the formation of a vast array of products including metal oxide, 30 − 33 hydroxide, 27 , 34 , 35 and even carboxylate 29 , 32 clusters ( Scheme 1 , path 3).…”