Cobalt-Catalyzed Intermolecular Markovnikov Hydroamination of Nonactivated Olefins: N²-Selective Alkylation of Benzotriazole

Cobalt-catalyzed Markovnikov-selective hydroamination of nonactivated olefins was developed. Hydrogen atom transfer from a catalytically generated cobalt(III)-hydride complex to the olefins proceeded regioselectively, and the nucleophilic addition of benzotriazoles occurred selectively at their N²-positions. The synthetic utility of the obtained N²-alkylated benzotriazoles as stable amine protecting groups under various reaction conditions was demonstrated, and the products were also transformed into primary amines by zinc-mediated reduction.