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Synlett 2005(16): 2492-2494  
DOI: 10.1055/s-2005-872694
LETTER
© Georg Thieme Verlag Stuttgart · New York

Hafnium Trifluoromethanesulfonate [Hf(OTf)4]-Catalyzed Conjugate ­Addition of Indoles to α,β-Enones

Motoi Kawatsura*a, Sachiko Aburatanib, Junichi Uenishib
a Department of Materials Science, Faculty of Engineering, Tottori University, Koyama, Tottori 680-8552, Japan
b Kyoto Pharmaceutical University, Misasagi, Yamashina, Kyoto 607-8412, Japan
Fax: +81(857)315179; e-Mail: kawatsur@chem.tottori-u.ac.jp;
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Publication History

Received 4 July 2005
Publication Date:
21 September 2005 (online)

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Abstract

Hafnium trifluoromethanesulfonate [Hf(OTf)4]- and scandium trifluoromethanesulfonate [Sc(OTf)3]-catalyzed conjugated addition of 3-position of indoles to several enones proceeded in acetonitrile as solvent. Especially, Hf(OTf)4 exhibited high catalytic ­activity and gave the conjugate addition product in good yield.

Key words

hafnium trifluoromethanesulfonate - conjugate additions - Lewis acids - indoles - enones - catalysis

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