Synthesis 2003(6): 0803-0819
DOI: 10.1055/s-2003-38674
REVIEW
© Georg Thieme Verlag Stuttgart ˙ New York

Radical-Mediated Annulation Reactions

Tara R. Rheault, Mukund P. Sibi*
Department of Chemistry, North Dakota State University, Fargo, North Dakota 58105 USA
Fax: +1(701)2311057; e-Mail: Mukund.Sibi@ndsu.nodak.edu;
Further Information

Publication History

Received 22 November 2002
Publication Date:
16 April 2003 (online)

Abstract

Radical annulation sequences have proven to be versatile and expedient routes towards highly complex cyclic frameworks. The radical annulation reaction allows for the formation of multiple carbon-carbon bonds in a single operation with regio- and stereocontrol. This review covers annulation reactions that have been carried out by four different pathways.

  • 1 Introduction

  • 2 Atom or Group Transfer Annulations

  • 3 Reductive Annulations

  • 3.1 Energy Diagram for Annulation Reaction

  • 3.2 Hybrid Radical-Ionic Annulation Sequence

  • 4 Fragmentation-Terminated Annulations

  • 4.1 Three-Component [2+2+2] Annulation

  • 5 Oxidative Radical Annulations

  • 5.1 Manganese(III) as an Oxidant

  • 5.2 Oxidative Radical Additions to Heteroaromatics

  • 6 Conclusions