PDF icon Download PDF
Synthesis 2004(5): 735-745  
DOI: 10.1055/s-2004-816005
SPECIALTOPIC
© Georg Thieme Verlag Stuttgart · New York

Allenic Compounds and Isothiocyanates as Key Building Units in the Synthesis of Heterocycles

Lambert Brandsma*a, Nina A. Nedolya*b
a Julianalaan 273, 3722-GN Bilthoven, The Netherlands
e-Mail: l.brandsma@wxs.nl;
b A. E. Favorsky Irkutsk Institute of Chemistry of the Russian Academy of Sciences, Siberian Branch, Favorsky Street 1, 664033 Irkutsk, Russia
e-Mail: nina@irioch.irk.ru;
Further Information

Publication History

Received 7 February 2004
Publication Date:
09 March 2004 (online)

   Permissions and Reprints All articles of this category
Preview

Abstract

Reaction between lithiated allenic compounds and isothiocyanates, R1N=C=S, in most cases gives exclusively thioimidates with the allenic structure, C=C=CC(SLi)=NR1. These intermediates have been used in novel approaches to 2,3-dihydropyridines, pyrroles, quinolines, cyclobutanopyrrolines, and thiophene or dihydrothiophene derivatives. The procedures leading to the heterocycles with a nitrogen atom in the ring involve S-alkylation followed by simple heating or by treatment with copper(I) halide. 2-Aminothiophenes and 2-imino-2,5-dihydrothiophenes are formed by intramolecular nucleophilic attack of the thiolate moiety on the allenic system and subsequent addition of methyl iodide or protonation.

  • 1 Introduction

  • 2 Generation of Allenic Lithium Compounds

  • 3 Formation of 2,3-Dihydropyridines or Mixtures of 2,3-Dihydropyridines and Pyrroles

  • 4 Directed Synthesis of Pyrroles

  • 5 Synthesis of Quinolines

  • 6 Synthesis of Cyclobutanopyrrolines

  • 7 Synthesis of Thiophene and Dihydrothiophene Derivatives

  • 8 Concluding Remarks

Key words

thioimidates - azatrienes - 2,3-dihydropyridines - pyrroles - quuinolines - cyclobutanopyrrolines - 2-aminothiophenes - 2-imino-2,5-dihydrothiophenes

14

Unpublished results from the author’s laboratory.