Synlett 2010(10): 1515-1518  
DOI: 10.1055/s-0029-1219944
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Selective Propargylation of Azo Compounds with Barium Reagents

Akira Yanagisawa*, Takanori Koide, Kazuhiro Yoshida
Department of Chemistry, Graduate School of Science, Chiba University, Inage, Chiba 263-8522, Japan
Fax: +81(43)2902789; e-Mail: ayanagi@faculty.chiba-u.jp;
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Publication History

Received 10 March 2010
Publication Date:
25 May 2010 (online)

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Abstract

A Barbier-type propargylation of azo compounds with γ-trialkylsilylated propargylic bromides has been achieved using reactive barium as a low-valent metal in THF. Corresponding propargylated hydrazines (α-adducts) were exclusively formed not only from azobenzenes (diaryldiazenes) but also from dialkyl azodicarboxylates. This method is also applicable to γ-alkylated or γ-phenylated propargylic bromides, providing the desired propargylated products only.