Synthesis of 4-Sulfenyl Isoxazoles through AlCl3-Mediated Electrophilic Cyclization and Sulfenylation of 2-Alkyn-1-one O-Methyloximes

An efficient method for the synthesis of 4-sulfenyl isoxazoles has been developed via AlCl3-mediated electrophilic cyclization/sulfenylation of 2-alkynone O-methyloximes. Remarkably, N-arylthiosuccinimides are employed as electrophiles for the construction of 4-arylthio isoxazoles, and 4-alkylthio isoxazoles are accessed with dialkyl disulfides as electrophiles.