New Isoxazole‐Substituted Aryl Iodides: Metal‐Free Synthesis, Characterization and Catalytic Activity

Abstract

A series of new isoxazole‐substituted aryl iodides 1a‐1d have been synthesized by DIB‐mediated [3+2] cycloaddition reaction of 2‐iodo‐1,3‐bis(prop‐2‐yn‐1‐yloxy) benzene (4) with corresponding benzaldehyde oximes 5a‐5d. Structure of the synthesized aryl iodides 1 were characterized by IR, 1HNMR, 13CNMR and HRMS. The structure of 1a was also confirmed by single crystal X‐ray crystallography. Further, catalytic activity of iodoarenes 1a‐1d was screened for the oxidation of hydroquinones and sulfides. On oxidation using aryl iodides 1 with m‐CPBA as terminal oxidant, hydroquinones afforded benzoquinones while sulfides gave corresponding sulfoxides in good to excellent yields. Iodoarene 1b showed the best catalytic activity for the oxidation of sulfides and hydroquinones. Moreover, iodoarene 1b, was also utilized for alpha‐oxytosylation of acetophenones. Keywords: aryl iodide; oxidation; oxytosylation; hydroquinone; sulfides