One- and two-electron oxidations and reductions of organoselenium and organotellurium compounds

Abstract

Publisher Summary Oxidation and reduction reactions of organotellurium and organoselenium compounds have provided much varied and interesting chemistry with respect not only to physical organic studies, but also to synthetic transformations. One electron oxidation to selenium- and tellurium-centered radical cations has allowed the comparison of substituent effects in various organoselenides and tellurides to the corresponding sulfides and oxygen-containing molecules. Two-electron oxidations of organotellurium and organoselenium compounds to the corresponding chalcogen compounds have been examined kinetically and, through the process of microscopic reversibility, have provided insight into the two-electron, reductive elimination process from chalcogen to chalcogen. Organochalcogen compounds have been used as synthetic reagents for the dehalogenation of vicinal-dihalides and for the reduction of α-halo ketones. Organochalcogen compounds have been utilized as halogenating agents and as mild oxidants for a variety of transformations. One-electron oxidation of organoselenium and organotellurium compounds results in initial formation of a radical cation. The eventual fate of the radical cation depends on several variables, but is typically a Se or Te compound. The chapter describes one-electron oxidation of selenides and tellurides that are not contained in a heteroaromatic compound, and ones in which the Se and Te are bonded to two carbons, rather than to other heteroatoms.