Cyclization of 1,2,4-triazenes to 1,2,4-triazoles using oxidizing reagents—NaClO, Ca(ClO)2, Dess–Martin periodinane and Ley's TPAP/NMO
摘要:
A simple and efficient approach to 1,3,5-trisubstituted 1,2,4-triazoles via cyclization of 1,2,4-triazenes employing commonly used oxidizing agents such as NaClO, Ca(ClO)(2), Dess-Martin periodinane and Ley's oxidizing agent (TPAP/NMO) is described. The reaction proceeds under mild conditions and is compatible with various functional groups. Extension of this approach to prepare triazoles on solid support has also been investigated. (C) 2001 Elsevier Science Ltd. All rights reserved.
From imidates to vinyl-1,2,4-triazoles: Synthesis, mechanistic aspects and first issues of their reactivity
作者:Safa Azzouni、Abderrahmen Abdelli、Anne Gaucher、Youssef Arfaoui、Mohamed Lotfi Efrit、Damien Prim
DOI:10.1016/j.tet.2018.10.050
日期:2018.12
The method reveals selective towards 5-vinyl-1,2,4-triazoles avoiding the potential formation of seven- and five-membered side-products as supported by theoretical calculations and NMR experiments. First lines of Pd-catalyzed arylation of the vinyl fragment towards 5-styryl-1,2,4-triazoles and Cu-catalyzed arylation at the N(1) site are finally described.
described using selective orthogonal arylation sequences. Ligand free Pd-catalyzed arylation allowed installing various (het)aryl units exclusively at the vinyl fragment of N1 substituted or N1-H precursors. Successful double arylations starting from ortho, meta and para bisiodobenzenes led to extended bistriazolyl derivatives. In contrast, Cu-catalyzed arylation using pyridylmethylamine as the ligand
An Improved Synthesis of 1,2,4-Triazoles using Ag2CO3
作者:K Paulvannan、Tao Chen、Ron Hale
DOI:10.1016/s0040-4020(00)00726-2
日期:2000.10
An improved synthesis of 1,3,5-trisubstituted 1,2,4-triazoles via Ag2CO3 mediated cyclization of triazenes has been developed. This approach is flexible and compatible with a wide range of functional groups. The reaction was complete within 3 h and the products were isolated in moderate to high yields. The influence of the beta-substituents of the amines on the triazole formation was also studied. (C) 2000 Elsevier Science Ltd. All rights reserved.
SHINE, HENRY J.;MANSURUL, HOQUE A. K. M., J. ORG. CHEM., 53,(1988) N 18, C. 4349-4353