Oxidation of Aryl Diphenylmethyl Sulfides Promoted by a Nonheme Iron(IV)-Oxo Complex: Evidence for an Electron Transfer-Oxygen Transfer Mechanism

详细信息    查看全文

• 作者：Alessia Barbieri ; Rosemilia De Carlo Chimienti ; Tiziana Del Giacco ; Stefano Di Stefano ; Osvaldo Lanzalunga ; Andrea Lapi ; Marco Mazzonna ; Giorgio Olivo ; Michela Salamone
• 刊名：Journal of Organic Chemistry
• 出版年：2016
• 出版时间：March 18, 2016
• 年：2016
• 卷：81
• 期：6
• 页码：2513-2520
• 全文大小：501K
• ISSN：1520-6904

文摘

The oxidation of a series of aryl diphenylmethyl sulfides (4-X-C₆H₄SCH(C₆H₅)₂, where X = OCH₃ (1), X = CH₃ (2), X = H (3), and X = CF₃ (4)) promoted by the nonheme iron(IV)-oxo complex [(N4Py)Fe^IV═O]²⁺ occurs by an electron transfer-oxygen transfer (ET-OT) mechanism as supported by the observation of products (diphenylmethanol, benzophenone, and diaryl disulfides) deriving from α-C–S and α-C–H fragmentation of radical cations 1^+•–4^+•, formed besides the S-oxidation products (aryl diphenylmethyl sulfoxides). The fragmentation/S-oxidation product ratios regularly increase through a decrease in the electron-donating power of the aryl substituents, that is, by increasing the fragmentation rate constants of the radical cations as indicated by a laser flash photolysis (LFP) study of the photochemical oxidation of 1–4 carried out in the presence of N-methoxyphenanthridinium hexafluorophosphate (MeOP⁺PF₆^–).