Iodine-Catalyzed Synthesis of Substituted Furans and Pyrans: Reaction Scope and Mechanistic Insights
作者:Domenic P. Pace、Raphaël Robidas、Uyen P. N. Tran、Claude Y. Legault、Thanh Vinh Nguyen
DOI:10.1021/acs.joc.1c00608
日期:2021.6.18
Substituted pyrans and furans are core structures found in a wide variety of natural products and biologically active compounds. Herein, we report a practical and mild catalytic method for the synthesis of substituted pyrans and furansusing molecular iodine, a simple and inexpensive catalyst. The method described is performed under solvent-free conditions at an ambient temperature and atmosphere,
Fe(II)/Au(I) Relay Catalyzed Propargylisoxazole to Pyridine Isomerization: Access to 6-Halonicotinates
作者:Alexey V. Galenko、Firuza M. Shakirova、Ekaterina E. Galenko、Mikhail S. Novikov、Alexander F. Khlebnikov
DOI:10.1021/acs.joc.7b00736
日期:2017.5.19
An efficient synthesis of methyl nicotinates/6-halonicotinates by the domino isomerization of 4-propargyl/(3-halopropargyl)-5-methoxyisoxazoles under Fe(II)/Au(I) relay catalysis was developed. It was found that FeNTf2 is an effective catalyst for first step of the domino isomerization, transformation of isoxazole to 2H-azirine, which is compatible with Ph3PAuNTf2, catalyzing the second step.
Under the acidic conditions, substituted furans were constructed from γ-alkynyl ketones through corresponding allene intermediates in one-pot. The methodology was also tailored to a series of the Ugi reaction products for the synthesis of 6-methylpyrazin-2(1H)-one derivatives. The current method offered significant advantages for the combinatorial applications of these chemical scaffolds.
Furan synthesis through AuCl3-catalysed cycloisomerisation of β-alkynyl β-ketoesters
作者:Arantxa Rodríguez、Wesley J. Moran
DOI:10.1016/j.tetlet.2011.03.086
日期:2011.5
AuCl3 efficiently catalyses the cycloisomerisation of readily available beta-alkynyl beta-ketoesters to generate trisubstituted furans. The substrate scope is wide and the reaction is high yielding and operationally simple. (C) 2011 Elsevier Ltd. All rights reserved.