N²‑Selective Iodofunctionalization of Olefins with NH-1,2,3-Triazoles to provide N²‑Alkyl-Substituted 1,2,3-Triazoles

A new method was developed to synthesize N²-alkyl-substituted 1,2,3-triazole through N-iodosuccinimide (NIS) mediated iodofuctionalization reaction of the alkene group with bi-, mono-, and unsubstituted NH-1,2,3-triazoles. The favored N-1 type hydrogen bond between the iodonium ion intermediate and 1,2,3-triazole was supposed to be generated, which gave the desired N²-alkyl triazole with a high N²-selectivity.