An efficient synthesis of bisisothiazole-4-yl disulfides via the demethoxylative thioannulation of alkynyl oxime ethers with odorless elemental sulfur has been first developed. This transformation involves the N–O bond cleavage, the formation of multiple C–S and N–S bonds, providing an efficient way for constructions of both isothiazoles and disulfides. Straightforward elaboration of the products to
A tandem protocol for the synthesis of fluorinated isoxazoles has been developed via catalytic intramolecular cyclizations of 2-alkynone O-methyl mimes 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.