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
作者:Davood Habibi、Ali Reza Faraji、Davood Sheikh、Masoome Sheikhi、Samaneh Abedi
DOI:10.1039/c4ra06463a
日期:——
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).
M@Si/Al (其中 M = Mn(III)、Co(II) 和 Fe(III))作为一种高效、可重复使用的异相催化剂,在二甲基甲酰胺(DMF)溶剂中用于 1-芳基-5-氨基-1H-四氮唑的区域特异性合成。在纳米金属催化剂的催化下,氰化物和叠氮化钠在热条件下发生反应,从而高效合成了芳基氨基四唑。从芳基环上带有释放电子取代基的芳基氰化物中可以得到 1-芳基-5-氨基-1H-四唑(B 异构体),而带有取电子基团的芳基氰化物则可以得到 5-芳基氨基-1H-四唑(A 异构体)。这种方法的优点包括产率高、反应时间相对较短、易于操作、催化剂可回收和重复使用以及催化剂吨位高。纳米催化剂可以很容易地回收并重复使用多次,而不会损失大量活性。利用密度泛函理论(DFT)方法,使用 6-31G 基集、几何和热力学参数、前沿分子轨道 (FMO) 以及分子静电位 (MEP) 对合成的组分进行了量子理论计算。