Iron-Catalyzed Highly Efficient Aerobic Oxidative Synthesis of Benzimidazoles, Benzoxazoles, and Benzothiazoles Directly from Aromatic Primary Amines Under Solvent-Free Conditions in the Open Air

2014-08-25T13:59:31Z (GMT) by Jiatao Yu Yonggen Xia Ming Lu
<div><p></p><p>Solvent-free oxidative synthesis of benzimidazoles, benzoxazoles, and benzothiazoles from aromatic primary amines and <i>o</i>-phenylenediamine, <i>o</i>-aminophenol, and <i>o</i>-aminothiophenol has been achieved by using Fe(NO<sub>3</sub>)<sub>3</sub> and TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxyl). This reaction can use air as an economical and green oxidant, and a wide variety of derivatives were obtained in good to excellent yields. The reaction mechanism was proposed and this method provides a direct, practical, and efficient approach for the preparation of substituted benzimidazoles, benzoxazoles, and benzothiazoles.</p> </div>