Synthesis 2004(4): 481-495  
DOI: 10.1055/s-2004-815973
REVIEW
© Georg Thieme Verlag Stuttgart · New York

Photochemical Cycloaddition between Benzene Derivatives and Alkenes

Norbert Hoffmann*
Laboratoire des Réactions Sélectives et Applications, UMR CNRS et Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, 51687 REIMS, Cedex 2, France
Fax: +33(3)26913166; e-Mail: norbert.hoffmann@univ-reims.fr;
Further Information

Publication History

Received 23 December 2003
Publication Date:
12 February 2004 (online)

Abstract

The photochemical cycloaddition of benzene derivatives with alkenes yield polycyclic compounds, which are of great interest in organic synthesis. Three modes are observed: [2+2] (ortho), [3+2] (meta) and, less frequently, [4+2] (para) photocycloaddition. The [3+2] cycloaddition has preferentially been studied and its intramolecular version was frequently applied to the synthesis of natural products. The [2+2] photocycloaddition is observed when electron active subsituents are present on the reaction partners. This mode is often followed by photochemical or thermal rearrangements. Furthermore, the [2+2] mode occurs concomitantly with the [3+2] photocycloaddition and leads frequently to complex reaction mixtures. More recent investigations deal with this item and show how the reaction may be directed to the [2+2] mode.

  • 1 Introduction

  • 2 [3+2] Photocycloaddition

  • 3 [2+2] Photocycloaddition

  • 4 [4+2] Photocycloaddition

  • 5 Other Related Photocycloaddtions with Benzene Derivatives

  • 6 Concluding Remarks