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Synfacts 2009(1): 0026-0026  
DOI: 10.1055/s-0028-1087459
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart ˙ New York

Au-Catalyzed Cycloisomerization of
N-Alkenyl Alkynylamides to 2-Pyridones

Contributor(s): Victor Snieckus, Jignesh J. Patel
H. Imase, K. Noguchi, M. Hirano, K. Tanaka*
Tokyo University of Agriculture and Technology, Japan
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Publication History

Publication Date:
18 December 2008 (online)

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Significance

Reported is a Au(I)/PPh3-catalyzed cycloisomerization of N-alkenyl alkynylamides to substituted 2-pyridones in fair to good yields. The starting amides were readily obtained by N-acylation of imines with alkynoyl chlorides. A cationic Au(I)/PPh3 complex gave the highest conversion while the use of a neutral Au(I)/PPh3 complex was catalytically inactive. The reaction appears to proceed through an endo-dig cyclization mode. Although little versatility in substitution patterns was achieved, 5,6-cyclofused 2-pyridones were obtained in high yields.