Metal-Free [2 + 2 + 1] Annulation of Alkynes, Nitriles, and Oxygen Atoms: Iodine(III)-Mediated Synthesis of Highly Substituted Oxazoles
Akio Saito*, Akihiro Taniguchi, Yui Kambara and Yuji Hanzawa
*Division of Applied Chemistry, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan, Email: akio-saicc.tuat.ac.jp
A. Saito, A. Taniguchi, Y. Kambara, Y. Hanzawa, Org. Lett., 2013, 15, 2672-2675.
DOI: 10.1021/ol4009816 (free Supporting Information)
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A metal-free annulation of alkynes, nitriles, and O-atoms, using PhIO as oxygen source, in the presence of TfOH or Tf2NH enables a regioselective assembly of 2,4-disubstituted and 2,4,5-trisubstituted oxazole compounds. The present reaction could be applied to a facile synthesis of an anti-inflammatory drug.
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