Copper-Mediated Sequential C–N and N–N Bond Formation: Facile Synthesis of Symmetrical 1,2,4-Triazoles
作者:Zhiguo Zhang、Guisheng Zhang、Zhonglian Li、Wei Zhang、Qingfeng Liu、Tongxin Liu
DOI:10.1055/s-0033-1338985
日期:——
Via a one-pot process, catalyzed by Cu(OAc)(2), a series of 3,5-disubstituted 4H-1,2,4-triazoles was conveniently and efficiently synthesized by using low-toxicity, stable, readily available, inexpensive amidine hydrochloride.
Copper-Catalyzed One-Pot Synthesis of 1,2,4-Triazoles from Nitriles and Hydroxylamine
A simple and efficient copper-catalyzed one-pot synthesis of substituted 1,2,4-triazoles through reactions of two nitriles with hydroxylamine has been developed. The protocol uses simple and readily available nitriles and hydroxylamine hydrochloride as the starting materials and inexpensive Cu(OAc)(2) as the catalyst, and the corresponding 1,2,4-triazole derivatives are obtained in moderate to good yields. The reactions include sequential intermolecular addition of hydroxylamine to one nitrile to provide amidoxime, copper-catalyzed treatment of the amidoxime with another nitrile, and intramolecular dehydration/cyclization. This finding provides a new and useful strategy for synthesis of 1,2,4-triazole derivatives.