Electron Transfer Mechanism in the Oxidation of Aryl 1-Methyl-1-phenylethyl Sulfides Promoted by Nonheme Iron(IV)-Oxo Complexes: The Rate of the Oxygen Rebound Process

Alessia Barbieri; Tiziana Del Giacco; Stefano Di Stefano; Osvaldo Lanzalunga; Andrea Lapi; Marco Mazzonna; Giorgio Olivo

doi:10.1021/acs.joc.6b02434

Electron Transfer Mechanism in the Oxidation of Aryl 1-Methyl-1-phenylethyl Sulfides Promoted by Nonheme Iron(IV)-Oxo Complexes: The Rate of the Oxygen Rebound Process

J Org Chem. 2016 Dec 16;81(24):12382-12387. doi: 10.1021/acs.joc.6b02434. Epub 2016 Dec 2.

Authors

Alessia Barbieri¹, Tiziana Del Giacco², Stefano Di Stefano¹, Osvaldo Lanzalunga¹, Andrea Lapi¹, Marco Mazzonna¹, Giorgio Olivo¹

Affiliations

¹ Dipartimento di Chimica and Istituto CNR di Metodologie Chimiche-IMC, Sezione Meccanismi di Reazione c/o Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza" , P. le A. Moro 5, 00185 Rome, Italy.
² Dipartimento di Chimica, Biologia e Biotecnologie and Centro di Eccellenza Materiali Innovativi Nanostrutturati, Università di Perugia , via Elce di sotto 8, 06123 Perugia, Italy.

PMID: 27978740
DOI: 10.1021/acs.joc.6b02434

Abstract

The oxidation of aryl 1-methyl-1-phenylethyl sulfides promoted by the nonheme iron(IV)-oxo complexes [(N4Py)Fe^IV═O]²⁺ and [(Bn-TPEN)Fe^IV═O]²⁺ occurs by an electron transfer-oxygen rebound (ET-OT) mechanism leading to aryl 1-methyl-1-phenylethyl sulfoxides accompanied by products derived from C_α-S fragmentation of sulfide radical cations (2-phenyl-2-propanol and diaryl disulfides). For the first time, the rate constants for the oxygen rebound process (k_OT), which are in the range of <0.8 × 10⁴ to 3.5 × 10⁴ s^-1, were determined from the fragmentation rate constants of the radical cations (k_f) and the S oxidation/fragmentation product ratios.

Publication types

Research Support, Non-U.S. Gov't