chitosan (as a linear polysaccharide) with a coppercomplex to expand the areas of its potential applications is an important scientific task. The present work reports the application of Cu(II)-5-amino-1H-tetrazole complex immobilized on modified magnetic chitosan as an effective catalyst (Fe3O4@Chitosan-Tet-Cu(II)) for C-N bond cross-coupling reaction between 5-aminotetrazole and aryl halides under
用铜络合物对壳聚糖(作为线性多糖)进行功能化以扩大其潜在应用领域是一项重要的科学任务。目前的工作报告了固定在改性磁性壳聚糖上的 Cu(II)-5-amino-1 H-四唑配合物作为CN 键交叉的有效催化剂 (Fe 3 O 4 @Chitosan-Tet-Cu(II)) 的应用。 5-氨基四唑和芳基卤化物在无配体条件下在二恶烷溶剂中的偶联反应。通过FT-IR、EDS、TEM、HRTEM、VSM、FFT、XRD、TG-DTG、ICP-MS和元素映射分析对制备的磁性纳米催化剂进行了表征。1-Aryl-5-amino-1 H-四唑以高产率生产。这种催化过程的优点包括方法简单、避免使用有害催化剂、反应时间短、产率高、易于处理和环境友好。Fe 3 O 4 @Chitosan-Tet-Cu(II) 催化剂即使在连续七次循环后仍表现出高效率和可重复使用性/可回收性,催化活性损失很小。
Magnetic chitosan-copper nanocomposite: A plant assembled catalyst for the synthesis of amino- and N-sulfonyl tetrazoles in eco-friendly media
作者:Narjes Motahharifar、Mahmoud Nasrollahzadeh、Asghar Taheri-Kafrani、Rajender S. Varma、Mohammadreza Shokouhimehr
DOI:10.1016/j.carbpol.2019.115819
日期:2020.3
A greener, cost efficient and simple method is described to prepare coppernanoparticles (NPs) immobilized on the magnetic chitosan (one of the more versatile polysaccharides) using Euphorbia falcata leaf extract as reducing/stabilizing agent. The prepared catalyst (Cu NPs@Fe3O4-chitosan) was authenticated by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), transmission
Solvent-free preparation of arylaminotetrazole derivatives using aluminum(III) hydrogensulfate as an effective catalyst
作者:Ferydoon Khamooshi、Ali Reza Modarresi-Alam
DOI:10.1016/j.cclet.2010.03.008
日期:2010.8
Abstract An efficient and simple method for the preparation of 5-arylamino-1H-tetrazole and 1-aryl-5-amino-1H-tetrazole derivatives is reported using aluminum(III) hydrogensulfate (Al(HSO4)3) as an effective heterogeneous catalyst from secondary arylcyanamides. Generally, when the substitution in arylcyanamide is strongly electron-withdrawing the position of equilibrium would shift toward the isomer
solvent. The experimental results indicated that the type of substituents on arylcyanamides could affect the type of products (A or Bisomer). The arylcyanamides with electron withdrawing and donating groups can produce isomer A (5-arylamino-1H-tetrazole) and isomerB (1-aryl-5-amino-1H-tetrazole), respectively. In addition, CS@Tet-IL-Cu(II) can be reused five times with no noteworthy loss of performance
Application of supported Mn(<scp>iii</scp>), Fe(<scp>iii</scp>) and Co(<scp>ii</scp>) as heterogeneous, selective and highly reusable nano catalysts for synthesis of arylaminotetrazoles, and DFT studies of the products
M@Si/Al (where M = Mn(III), Co(II) and Fe(III) supported on nanosized SiO2/Al2O3) is applied as an efficient, highly reusable and heterogeneous catalyst for the regiospecific synthesis of 1-aryl-5-amino-1H-tetrazole in dimethylformamide (DMF) as a solvent. The arylaminotetrazoles were efficiently synthesized from the reaction of cyanamides and sodium azide in the presence of a catalytic amount of nano metal catalyst under thermal conditions. 1-Aryl-5-amino-1H-tetrazoles (B isomer) can be obtained from the arylcyanamides carrying electron releasing substituents on the aryl ring, while with electron withdrawing groups, 5-arylamino-1H-tetrazole (A isomer) will be obtained. The advantages of this method include high yields, relatively short reaction times, easy work-up, recovery and reusability of the catalyst and high TON of catalyst. The nano catalyst can be easily recovered and reused several times without considerable loss of activity. The quantum theoretical calculations for the synthesized components were performed by density functional theory (DFT) methods using the 6-31G basis set, geometry and thermodynamic parameters, frontier molecular orbitals (FMOs) as well as by using molecular electrostatic potentials (MEPs).