File(s) under permanent embargo

Reason: This item is currently closed access.

Iron(III) bromide catalyzed bromination of 2-tert-butylpyrene and corresponding position-dependent aryl-functionalized pyrene derivatives

journal contribution
posted on 07.09.2015, 08:26 authored by Xing Feng, Jian-Yong Hu, Hirotsugu Tomiyasu, Zhu Tao, Carl Redshaw, Mark ElsegoodMark Elsegood, Lynne Horsburgh, Simon J. Teat, Xian-Fu Wei, Takehiko Yamato
The present work probes the bromination mechanism of 2-tert-butylpyrene (1), which regioselectively affords mono-, di-, tri- and tetra-bromopyrenes, by theoretical calculation and detailed experimental methods. The bromine atom may be directed to the K-region (positions 5- and 9-) instead of the more reactive 6- and 8-positions in the presence of iron powder. In this process, FeBr3 plays a significant role to release steric hindrance or lower the activation energy of the rearrangement. The intermediate bromopyrene derivatives were isolated and confirmed by 1H NMR spectrometry, mass spectroscopy and elemental analysis. Further evidence on substitution position originated from a series of aryl substituted pyrene derivatives, which were obtained from the corresponding bromopyrenes on reaction with 4-methoxy-phenylboronic acid by a Suzuki–Miyaura cross-coupling reaction. All position-dependent aryl-functionalized pyrene derivatives are characterized by single X-ray diffraction, 1H/13C NMR, FT-IR and MS, and offered straightforward evidence to support our conclusion. Furthermore, the photophysical properties of a series of compounds were confirmed by fluorescence and absorption, as well as by fluorescence lifetime measurements.

History

School

  • Science

Department

  • Chemistry

Published in

RSC ADVANCES

Volume

5

Issue

12

Pages

8835 - 8848 (14)

Citation

FENG, X. ...et al., 2015. Iron(III) bromide catalyzed bromination of 2-tert-butylpyrene and corresponding position-dependent aryl-functionalized pyrene derivatives. RSC Advances, 5(12), pp.8835-8848.

Publisher

© The Royal Society of Chemistry

Version

AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Publication date

2015

Notes

This paper is closed access.

ISSN

2046-2069

Language

en