Synthesis 2017; 49(20): 4676-4686
DOI: 10.1055/s-0036-1589071
special topic
© Georg Thieme Verlag Stuttgart · New York

Improved Synthesis of Symmetrical 2,5-Diarylimidazoles by One-Pot Palladium-Catalyzed Direct Arylation Tailored on the Electronic Features of the Aryl Halide

Marco Lessi
a   Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy   Email: fabio.bellina@unipi.it
,
Gianmarco Panzetta
a   Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy   Email: fabio.bellina@unipi.it
,
Giulia Marianetti
b   Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
,
a   Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy   Email: fabio.bellina@unipi.it
› Author Affiliations
This work was supported by the Università di Pisa under the projects PRA 2015 (project no. 2015_0038) and PRA 2017 (project no. 2017_28).
Further Information

Publication History

Received: 22 May 2017

Accepted after revision: 19 June 2017

Publication Date:
31 July 2017 (online)


Dedicated to Prof. Renzo Rossi on the occasion of his 80th birthday

Published as part of the Special Topic Modern Strategies for Heterocycles Synthesis

Abstract

Two methods for the one-pot synthesis of 2,5-diarylimidazoles by palladium-catalyzed direct C–H arylation of 1-substituted imidazoles with aryl bromides have been devised. The first method, promoted by copper(I) iodide, is best suited for electron-poor aryl bromides, and also allows the 2,5-diarylation of thiazole and oxazole. The use of xylene instead of DMA is the key for the efficiency of the second method, which gives the best results with electron-rich aryl bromides.

Supporting Information