An Effective Nitrilimine Cycloaddition for the Synthesis of 1,3,5-Trisubstituted 1,2,4-Triazoles from Oximes with Hydrazonoyl Hydrochlorides
摘要:
An effective 1,3-dipolar cycloaddition for the synthesis of 1,3,5-trisubstituted 1,2,4-triazole derivatives was developed by reacting oximes with hydrazonoyl hydrochlorides using triethylamine as a base. The desired 1,3,5-trisubstituted 1,2,4-triazoles were obtained in good yields and the reaction was applicable to aliphatic, cyclic aliphatic, aromatic and heterocyclic oxime substrates.
A novel [1+1+3] annulation of AgNOx, isocyanides, and isocyanates for the selective synthesis of 1,2,4-triazoles is presented herein. In this transformation, AgNOx and isocyanates are used as nitrogen sources instead of the traditional hydrazine or diazonium reagents. This process also involves N–O/C–H/C═N bond cleavage and the construction of new N–N/C–N bonds with a good substrate scope and functional
Cycloaddition reactions of glycine imine anions to phenylazocarboxylic esters – a new access to 1,3,5-trisubstituted 1,2,4-triazoles
作者:Roman Lasch、Markus R. Heinrich
DOI:10.1016/j.tet.2015.04.078
日期:2015.6
Phenylazocarboxylic tert-butyl esters have recently been shown to be highly versatile building blocks due to their ability to undergo nucleophilic aromatic substitutions under mild conditions, particularly well with [F-18]fluoride, and to act as precursors for aryl radicals. In this article, we now report first examples for cycloaddition reactions to phenylazocarboxylates. In a one-pot reaction with readily accessible glycine imines, a variety of highly substituted 1,2,4-triazoles could be obtained. (C) 2015 Elsevier Ltd. All rights reserved.
Synthesis and antiproliferative evaluation of 3,5-disubstituted 1,2,4-triazoles containing flurophenyl and trifluoromethanephenyl moieties
作者:Li-Ya Wang、Wen-Che Tseng、Tian-Shung Wu、Kimiyoshi Kaneko、Hiroyuki Takayama、Masayuki Kimura、Wen-Chin Yang、Jin Bin Wu、Shin-Hun Juang、Fung Fuh Wong
DOI:10.1016/j.bmcl.2011.07.009
日期:2011.9
An efficient 1,3-dipolar cycloaddition method was performed for the synthesis of a series of monofluoroand trifluoromethane-3,5-disubstituted 1,2,4-triazoles. This efficient cycloaddition method was to react hydrazonoyl hydrochlorides with a series of aldehydes in the presence of NEt(3) as catalytic basic agent to provide the corresponding product in 28-94%. Their growth inhibitory results against cancer cells indicated that some of the fluorine-and trifluoromethane-containing compounds could effectively inhibit the growth of NCI-H226 and T-cell leukemia (Jurkat) cells. Among the compounds, trifluoromethane-containing 1,2, 4-triazoles possessed the five-membered ring groups on the C-5 position of the triazolic ring, including cyclopentyl, 3-furyl, 3-thienyl, and 2-pyrrolyl, possessed the significant inhibitory activity for NCI-H226 cancer cells. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
‘One-flask’ synthesis to 3,5-disubstituted 1,2,4-triazoles from aldehydes with hydrazonoyl hydrochlorides via 1,3-dipolar cycloaddition
作者:Wen-Che Tseng、Li-Ya Wang、Tian-Shung Wu、Fung Fuh Wong
DOI:10.1016/j.tet.2011.05.003
日期:2011.7
A new 'one-flask' synthesis of 3,5-disubstituted 1,2,4-triazoles has successfully been developed to synthesize a series of 3,5-disubstituted 1,2,4-triazoles. The transformation involves the 1,3-dipolar cycloaddition reaction of hydrazonoyl hydrochlorides with oxime intermediates prepared from aldehydes with hydroxylamine hydrochloride in the presence of excess amount of triethylamine. In this 'one-flask' 1,3-dipolar reaction, hydrazonoyl hydrochlorides was concerned as the masked 1,3-dipole nitrilimine under basic condition. Furthermore, this newly developed methodology can be applied to various aldehyde substrates including aliphatic, cyclic aliphatic, aromatic, and heterocyclic aldehydes. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.