Arylazide Cycloaddition to Methyl Propiolate: DFT-Based Quantitative Prediction of Regioselectivity
作者:Giorgio Molteni、Alessandro Ponti
DOI:10.1002/chem.200204681
日期:2003.6.16
3-triazoles have been synthesized by 1,3-dipolar cycloaddition of the corresponding arylazides to methylpropiolate in carbon tetrachloride. The regioselectivity of these reactions cannot be rationalized on the basis of the electronic demands of the reactants or frontier molecular-orbital theory. Therefore, we applied to this problem a quantitative formulation of the HSAB principle to this problem
Hyperbranched polyethylenimine-supported copper(II) ions as a macroliganted homogenous catalyst for strict click reactions of azides and alkynes in water
作者:Hicham Ben El Ayouchia、Hamid ElMouli、Lahoucine Bahsis、Hafid Anane、Rachid Laamari、Carlos J. Gómez-García、Miguel Julve、Salah-Eddine Stiriba
DOI:10.1016/j.jorganchem.2019.120881
日期:2019.10
Loading hyperbranched polyethylenimine (PEI) with copper(II) ions leads to the formation of a new water-soluble metallodendritic polymer Cu(II)-PEI that has been found to effectively catalyze the clickable azide-alkyne [3 + 2] cycloaddition reactions in water under ambient conditions, in the lack of any external reducing agent. A positive dendritic effect on the catalyst activity was observed in the
Direct access to 1,4-disubstituted 1,2,3-triazoles through organocatalytic 1,3-dipolar cycloaddition reaction of α,β-unsaturated esters with azides
作者:Wenjun Li、Xiao Zhou、Yepeng Luan、Jian Wang
DOI:10.1039/c5ra19038j
日期:——
DBU-catalyzed organocatalytic 1,3-dipolarcycloadditionreactions of α,β-unsaturated esters with azides have been developed. This strategy generates 1,4-disubstituted 1,2,3-triazoles in high yields with high regioselectivities. It is demonstrated that some of these products can be transformed into important pharmaceutical agents.
Development of a tandem ‘click-click’ approach to the formation of successive 1,4-disubstituted 1,2,3-triazole linkages and ‘click chemistry’ on sugar-derived alkynes are described.
Silver(I) oxide nanoparticles as a catalyst in the azide–alkyne cycloaddition
作者:Anna M. Ferretti、Alessandro Ponti、Giorgio Molteni
DOI:10.1016/j.tetlet.2015.08.083
日期:2015.10
1,3-Dipolar cycloadditions between a number of azides and monosubstituted acetylenes have been carried out in the presence of catalytic amounts of silver(l) oxide nanoparticles. 4-Substituted 1,2,3-triazoles were usually the only products, while the presence of electron-withdrawing groups onto the azide moiety caused a loss of regioselectivity giving mixtures of 4- and 5-substituted 1,2,3-triazoles. A novel catalytic cycle has been proposed to rationalize this latter 'non-click' behaviour. (C) 2015 Elsevier Ltd. All rights reserved.