Synlett 2008(6): 787-800  
DOI: 10.1055/s-2008-1042933
ACCOUNT
© Georg Thieme Verlag Stuttgart · New York

Aryl Cation Chemistry as an Emerging Versatile Tool for Metal-Free Arylations

Valentina Dichiarante, Maurizio Fagnoni*
Department of Organic Chemistry, University of Pavia, 27100 Pavia, Italy
Fax: +39(0382)987323; e-Mail: fagnoni@unipv.it;
Further Information

Publication History

Received 26 November 2007
Publication Date:
11 March 2008 (online)

Abstract

The development of transition-metal-free arylation procedures represents a key goal in modern organic synthesis. A green arylation can be obtained by having recourse to light as a ‘clean’ reagent in place of toxic metals. In particular, a new method based upon the photoheterolytic fragmentation of substituted aryl halides or esters, with the formation of aryl cations has recently emerged. The peculiar reactivity of these cations with carbon nucleophiles allows several straightforward photo-arylations, which compare favorably with other thermal or photochemical metal-free analogues.

1 Introduction

2 Aryl Cation Chemistry

3 Metal-Free Formation of Aryl-Carbon Bonds

3.1 Formation of Aryl-Alkyl Bonds

3.1.1 Arylation of Carbonyl Compounds

3.1.2 Formation of Aryl-Allyl Bonds

3.1.3 Formation of Other Aryl-Alkyl Bonds

3.2 Formation of Aryl-Vinyl Bonds

3.3 Formation of Aryl-Alkynyl Bonds

3.4 Formation of Aryl-Aryl Bonds

3.5 Cyanation

4 Conclusions

6

Dichiarante, V.; Fagnoni, M.; Albini, A. Photochemical Arylation Reactions, In Modern Arylation Methods; Ackermann, L., Ed.; Wiley-VCH: Weinheim, in preparation.

49

Protti, S.; Dondi, D.; Fagnoni, M.; Albini, A. Eur. J. Org. Chem., accepted for publication.