Neutral Te(II) species 2-(tBuNCH)C6H4TeCl (ICl) as well as tellurenyl Te(II)+ cations 2-(tBuNCH)C6H4TeX (X = OTf or SbF6), i.e., IOTf and ISbF6, exhibit a wide range of reactivity toward various ortho-quinones. While the reaction of ortho-chloranil leads to the oxidation of Te(II) into Te(IV), 3,5-di-tert-butyl-ortho-benzoquinone leads only to partial oxidation due to an ongoing dynamic reversible reaction, being the first example of a chemically reversible two electron Te(II)/Te(IV) redox couple. By contrast, 9,10-phenanthrenequinone as a very weak oxidant shows no reaction; however, the most Lewis acidic ISbF6 produces a corresponding Lewis adduct interacting by both electrostatic and weak chalcogen bond interactions. The diverse reactivity scope is further complemented by DFT computed thermochemistry data. Furthermore, IOTf is successfully utilized for the catalytic transfer of silanes (Et3SiH, Ph3SiH, Ph2SiH2, and (EtO)3SiH) to ortho-quinones via redox single or double Si-H bond activation, yielding silylated catechols, monomeric cyclic catecholatosilanes, or bis(catecholato)silanes. Surprisingly, in the absence of the catalyst IOTf, the reactivity spans from no reaction to the formation of hexachloro-dibenzo1,4dioxine-2,3-dione. The latter product is an entirely different substance class compared to the one formed during the catalyzed reaction.
Hejda et al. (Thu,) studied this question.