American Chemical Society
jo5008702_si_002.cif (24.23 kB)

Direct Synthesis of 4‑Fluoroisoxazoles through Gold-Catalyzed Cascade Cyclization–Fluorination of 2‑Alkynone O‑Methyl Oximes

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posted on 2014-07-18, 00:00 authored by Yunkyung Jeong, Bom-I Kim, Jae Kyun Lee, Jae-Sang Ryu
A tandem protocol for the synthesis of fluorinated isoxazoles has been developed via catalytic intramolecular cyclizations of 2-alkynone O-methyl oximes and ensuing fluorination. The reactions proceed smoothly at room temperature in the presence of 5 mol % of (IPr)­AuCl, 5 mol % of AgOTs, 2.5 equiv of Selectfluor, and 2 equiv of NaHCO3. This process features an efficient one-pot cascade route to fluoroisoxazoles with high yields and high selectivity under mild reaction conditions.