Herein, we describe a novel synthetic method for 2,5-disubstituted tetrazoles from 5-substituted tetrazoles using cobalt-catalyzed intermolecular hydroamination reaction of nonactivated olefins. Owing to its mild conditions, the method enabled the use of substrates having acid-labile functional groups, such as silyloxy and methoxymethyloxy groups. By using optically active cobalt complexes, asymmetric intermolecular hydroamination of nonactivated olefins, a longstanding challenge in synthetic organic chemistry, was developed to produce optically active disubstituted tetrazoles.
Keywords: asymmetric synthesis; cobalt catalyst; hydroamination; tetrazole.