ONE-POT SYNTHESIS OF POLYSUBSTITUTED IMIDAZOLES FROM ARYLALDEHYDES IN WATER CATALYZED BY NHC USING MICROWAVE IRRADIATION
摘要:
A simple, high yielding synthesis of tri (3a-i) and tetrasubstituted (4a-g) imidazols from aldehydes is described. The cornerstone of this methodology involves the condensation of NH4OAc, substituted aldehydes, and benzoin, which is synthesized in situ from aldehydes catalyzed by N-heterocyclic carbine (NHC), under microwave irradiation in water to afford trisubstituted imidazoles (3a-i). If arylamine is added in the solution, tetrasubstituted imidazoles (4a-g) can be obtained. Lepidilines B and trifenagrel are also synthesized in high yield using this procedure. All the experiment deta are in agreement with the literature.
Synthesis of organosilyl compounds-containing 1,2,4,5-tetraaryl imidazoles sonocatalyzed by M/SAPO-34 (M = Fe, Co, Mn, and Cu) nanostructures
作者:Kazem D. Safa、Maryam Allahvirdinesbat、Hassan Namazi、Parvaneh Nakhostin Panahi
DOI:10.1016/j.crci.2015.04.008
日期:2015.8
Résumé The one-step synthesis of silylated 1,2,4,5-tetraaryl imidazoles by use of a series of M/SAPO-34 (M: Fe, Co, Mn, and Cu) nanocatalysts and subsequent silylation reactions is described. Cu/SAPO-34 catalyst has the highest activity in improving the efficiency of the heterogeneous cyclo-condensation of an aldehyde, benzil, ammonium acetate and a primary aromatic amine in water under ultrasonic irradiation. Some of imidazole derivatives are studied with a view to the synthesis of a series of new, multi-substituted imidazoles containing organosilyl groups including carbosilanes (Si–C) and silyl ethers (Si–O). Supplementary Materials: Supplementary material for this article is supplied as a separate file: mmc1.docx
Visible light-emitting diode light-driven one-pot four component synthesis of poly-functionalized imidazoles under catalyst- and solvent-free conditions
作者:Geetika Patel、Ashok Raj Patel、Subhash Banerjee
DOI:10.1039/d0nj02527e
日期:——
A visible light-emitting diode light-driven green and sustainable protocol has been demonstrated for the one-pot four component synthesis of poly-functionalized imidazoles under catalyst- and solvent-free conditions.
One-Pot Synthesis of Polysubstituted Imidazoles Based on Pd(OAc)2/Ce(SO4)2/Bi(NO3)3 Trimetallic Cascade of Decarboxylation/Wacker-Type Oxidation/Debus–Radziszewski Reaction
作者:Wei Sun、Mingjuan Zhang、Peilang Li、Yiqun Li
DOI:10.1055/s-0037-1611835
日期:2019.9
Abstract A novel and highly efficient one-pot synthesis of polysubstituted imidazoles from α-hydroxyphenylacetic acids, diphenylacetylene, and amines has been achieved by Pd(OAc)2/Ce(SO4)2/Bi(NO3)3 trimetallic catalytic system. A series of control experiments showed that this overall reaction occurs through a one-pot cascade process combining the steps of decarboxylation of α-hydroxyphenylacetic acids
spectrophotometer and high- resolution transmission electron microscopy These synthesized γ-Al 2 O 3 NPs were tested used as a catalyst for one pot synthesis of tetraaryl imidazole derivatives from the cyclodehydration and condensation of benzil, aromatic aldehyde, anilines and ammonium acetate under solvent free condition. This method has various advantages like convenient work-up procedure, environmentally
通过电化学还原法成功地合成了γ-氧化铝纳米粒子(γ-Al2 O 3 NPs)。溴化四丙基铵的水溶液用作电解质和稳定剂。为了防止自发团聚并控制纳米颗粒的尺寸,对各种参数(例如电流密度,电极之间的距离和电解质浓度)进行了优化。由此合成的γ-Al2O3NPs通过复杂的分析技术进行了表征,包括X射线衍射,扫描电子显微镜,能量色散分光光度计和高分辨率透射电子显微镜。这些合成的γ-Al2 O 3 NPs被用作一锅催化剂。由苯甲醚,芳族醛的环脱水和缩合反应合成四芳基咪唑衍生物 无溶剂条件下的苯胺和乙酸铵。该方法具有多种优点,如后处理方便,对环境无害,反应时间短以及产率高。纳米晶γ-Al2 O 3催化剂具有易于获得,多次循环利用,非常简单的分离和生态友好的特点。
Cu(II) immobilized on guanidinated epibromohydrin‐functionalized γ‐Fe<sub>2</sub>O<sub>3</sub>@TiO<sub>2</sub>(γ‐Fe<sub>2</sub>O<sub>3</sub>@TiO<sub>2</sub>‐EG‐Cu(II)): A highly efficient magnetically separable heterogeneous nanocatalyst for one‐pot synthesis of highly substituted imidazoles
A simple, efficient and eco‐friendly procedure has been developed using Cu(II) immobilized on guanidinated epibromohydrin‐functionalized γ‐Fe2O3@TiO2 (γ‐Fe2O3@TiO2‐EG‐Cu(II)) for the synthesis of 2,4,5‐trisubstituted and 1,2,4,5‐tetrasubstituted imidazoles, via the condensation reactions of various aldehydes with benzil and ammonium acetate or ammonium acetate and amines, under solvent‐free conditions