Stepwise Mechanism for the Bromination of Arenes by a Hypervalent Iodine Reagent
Granados Toda, Albert (Universitat Autònoma de Barcelona. Departament de Química)
Shafir, Alexandr (Institut de Química Avançada de Catalunya. Departament de Química Biològica)
Arrieta, Ana (Universidad del País Vasco. Departamento de Química Orgánica)
Cossío, Fernando P. (Centro de Innovación en Química Avanzada (ORFEO-CINQA))
Vallribera Massó, Adelina (Universitat Autònoma de Barcelona. Departament de Química)

Date:	2020
Abstract:	A mild, metal-free bromination method of arenes has been developed using the combination of bis(trifluoroacetoxy)iodobencene and trimethylsilyl bromide. In situ-formed dibromo(phenyl)-λ3-iodane (PhIBr2) is proposed as the reactive intermediate. This methodology using PIFA/TMSBr has been applied with success to a great number of substrates (25 examples). The treatment of mono-substituted activated arenes led to para-brominated products (2u-z) in excellent 83-96% yields. Density functional theory calculations indicate a stepwise mechanism involving a double bromine addition followed by a type II dyotropic reaction with concomitant re-aromatization of the six-membered ring.
Grants:	Agencia Estatal de Investigación CTQ2017-86936-P Agencia Estatal de Investigación CTQ2016-80375-P Agencia Estatal de Investigación RTI2018-097853-B-I00 Agencia Estatal de Investigación CTQ2016-81797-REDC Agencia Estatal de Investigación RED2018-102387-T Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-465
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Published in:	Journal of organic chemistry, Vol. 85, Issue 4 (February 2020) , p. 2142-2150, ISSN 1520-6904

DOI: 10.1021/acs.joc.9b02784

Postprint 26 p, 1.0 MB

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