Diverse Reactions of Thiophenes, Selenophenes, and Tellurophenes with Strongly Oxidizing I(III) PhI(L)2 Reagents
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- 作者：Sathsara Egalahewa ; Mohammad Albayer ; Antonino Aprile ; Jason L. Dutton
- 刊名：Inorganic Chemistry
- 出版年：2017
- 出版时间：February 6, 2017
- 年：2017
- 卷：56
- 期：3
- 页码：1282-1288
- 全文大小：379K
- ISSN：1520-510X
文摘
We report the outcomes of the reactions of aromatic group 16 thiophene, selenophene, and tellurophene rings with the I(III) oxidants PhI(OAc)(OTf) and [PhI(Pyr)2][OTf]2 (Pyr = pyridine). In all reactions, oxidative processes take place, with generation of PhI as the reduction product. However, with the exception of tellurophene with PhI(OAc)(OTf), +4 oxidation state complexes are not observed, but rather a variety of other processes occur. In general, where a C–H unit is available on the 5-membered ring, an electrophilic aromatic substitution reaction of either −IPh or pyridine onto the ring occurs. When all positions are blocked, reactions with PhI(OAc)(OTf) give acetic and triflic anhydride as the identifiable oxidative byproducts, while [PhI(Pyr)2][OTf]2 gives pyridine electrophilic aromatic substitution onto the peripheral rings. Qualitative mechanistic studies indicate that the presence of the oxidizable heteroatom is required for pyridine to act as an electrophile in a substantial manner.