Cationic Gold(I)-Mediated Intramolecular Cyclization of 3-Alkyne-1,2-diols and 1-Amino-3-alkyn-2-ols: A Practical Route to Furans and Pyrroles
Masahiro Egi, Kenji Azechi and Shuji Akai*
*School of Pharmaceutical Sciences, University of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka, Shizuoka 422-8526, Japan, Email: akaiu-shizuoka-ken.ac.jp
M. Egi, K. Azechi, S. Akai, Org. Lett., 2009, 11, 5002-5005.
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Intramolecular cyclizations of 3-alkyne-1,2-diols and 1-amino-3-alkyn-2-ols with very low catalyst loading of (Ph3P)AuCl-AgNTf2 or (Ph3P)AuCl-AgOTf proceeded at room temperature to provide various substituted furans and pyrroles in excellent yields. This method was also fully applicable to the conversion of 26 g of a substrate using only 0.05 mol % each of the Au and Ag catalysts.
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