Highly N-2-Selective Allylation Of Nh-1,2,3-Triazoles With Allenamides Mediated By N-Iodosuccinimide

A new method was developed to synthesize N-2-allyl-substituted 1,2,3-triazoles via NIS mediated allylation of allenamides with mono- and unsubstituted NH-1,2,3-triazoles and benzotriazole. All the N-2-allyl-substituted 1,2,3-triazoles have a relative stability. The ionic pair composed of a sigma-complex and the conjugate base of the imide and the hydrogen bond between the conjugate base and NH-1,2,3-triazole were found to be generated, which selectively gave the desired N-2-allylation products.