Synlett 2008(9): 1269-1278  
DOI: 10.1055/s-2008-1072743
ACCOUNT
© Georg Thieme Verlag Stuttgart · New York

1,7-Electrocyclizations of Azomethine Ylides: Scope and Synthetic Aspects

Miklós Nyerges*a, Judit Tótha, Paul W. Groundwaterb
a Research Group of the Hungarian Academy of Sciences, Department of Organic Chemistry and Technology, Technical University of Budapest, P.O.B. 91, 1521 Budapest, Hungary
Fax: +36(1)4632213; e-Mail: mnyerges@mail.bme.hu;
b Sunderland Pharmacy School - Drug Design and Analysis, Sunderland Pharmacy School, University of Sunderland, Sunderland SR1 3SD, UK
Further Information

Publication History

Received 4 January 2008
Publication Date:
16 April 2008 (online)

Abstract

The 1,3-dipolar cycloaddition of azomethine ylides is a versatile and efficient tool for the construction of five-membered nitrogen heterocycles. When the azomethine ylide is conjugated with double bonds other pericyclic pathways become available, including 1,5- or 1,7-electrocyclizations, with the latter 8π-electron process having only recently emerged as a potentially useful method for the formation of seven-membered heterocycles. Under special structural circumstances, multistep rearrangements can also be observed. In this account, a summary of our work on the exploration and development of 1,7-electrocyclizations of azomethine ylides is presented.

1 Introduction

2 Electrocyclizations

2.1 Reaction of β-Phenylcinnamaldehyde with Amino Acids: The First 1,7-Electrocyclization of Nonstabilized Azomethine Ylides

2.2 Synthesis of Azepines from Unsaturated Aldehydes and Sarcosine via 1,7-Electrocyclizations

2.3 Electrocyclizations of Stabilized Azomethine Ylides

2.4 Electrocyclizations of Azomethine Ylides onto a N=O Double Bond

3 Conclusions

1

Current address: Servier Research Institute of Medicinal Chemistry, 1131 Budapest Záhony u. 7, Hungary.