Synthesis of Tetrasubstituted Furans through One-Pot Formal [3 + 2] Cycloaddition Utilizing [1,2]-Phospha-Brook Rearrangement
Azusa Kondoh, Kohei Aita, Sho Ishikawa and Masahiro Terada*
*Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan, Email: mteradatohoku.ac.jp
A. Kondoh, K. Aita, S. Ishikawa, M. Terada, Org. Lett., 2020, 22, 2105-2110.
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A [1,2]-phospha-Brook rearrangement under Brønsted base catalysis enables an efficient synthesis of 2,4,5-trisubstituted-3-iodofurans via a formal [3 + 2] cycloaddition of an in situ generated α-oxygenated propargyl anion to an aldehyde and a subsequent intramolecular cyclization mediated by N-iodosuccinimide. The method provides access to a wide range of tetrasubstituted furans.
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proposed reaction pathway
furans, Brook rearrangement, NIS