A green metal-free “one-pot” microwave assisted synthesis of 1,4-dihydrochromene triazoles
作者:Tânia M. F. Alves、Guilherme A. M. Jardim、Marco A. B. Ferreira
DOI:10.1039/d1ra01169c
日期:——
The synthesis of several 4-aryl-1,4-dihydrochromene-triazoles was achieved via a metal-free “one-pot” procedure using PEG400 as the sole solvent in an eco-friendly process. Using microwave irradiation, the triazole derivatives were obtained in good yields and short reaction times starting from readily accessible building blocks.
A facile and new metal-free 1,3-dipolarcycloaddition reaction for the synthesis of 4-aryl-NH-1,2,3-triazoles from nitroolefins and NaN3 employing NH2SO3H has been developed. Sulfamic acid proved to be an efficient additive in this transformation by inhibiting the formation of triaryl benzene. Mechanistic aspects and key intermediates associated with this transformation have also been characterized
Catalyst-free 1,3-dipolar cycloaddition of 3-nitrochromen with sodium azide: a facile method for the synthesis of 4-aryl-1,4-dihydrochromeno[4,3-d][1,2,3]triazole derivatives
作者:Pateliya Mujjamil Habib、B. Rama Raju、Veerababurao Kavala、Chun-Wei Kuo、Ching-Fa Yao
DOI:10.1016/j.tet.2009.05.002
日期:2009.7
1,3-Dipolar cycloaddition of 3-nitrochromen with sodium azide under catalyst-free conditions afforded 4-aryl-1,4-dihydrochromeno[4,3-d][1,2,3]triazole derivatives at 80 degrees C in DMSO is described. The generality of this reaction was demonstrated by synthesizing an array of 4-aryl-1,4-dihydrochromeno[4,3d][1,2,3]triazole derivatives. Clean reaction conditions, easy isolation, and good yields of the triazoles are the salient features of the methodology. (C) 2009 Elsevier Ltd. All rights reserved.