An enantioselectiveBiginellireaction that proceeds by a dual-activation route has been developed by using a combined catalyst of a readily available trans-4-hydroxyproline-derived secondary amine and a Bronsted acid. Aromatic, heteroaromatic, and fused-ring aldehydes were found to be suitable substrates for this multicomponent reaction. The corresponding dihydropyrimidines were obtained in moderate-to-good
catalyzed solvent-free synthesis for new heterocyclic compounds is described. A series of heterocyclic compounds can be readily obtained using the three-component reaction of diketones, aldehydes and 2-amino benzothiazole, urea or thiourea. The mechanism of the three component kaolin catalyzed Biginelli (using urea and thiourea) and Biginelli like (using 2-amino benzothiazole) reaction has been investigated
描述了用于新的杂环化合物的高岭土催化的无溶剂合成。使用二酮,醛和三酮的三组分反应可以轻松获得一系列杂环化合物2-氨基苯并噻唑, 尿素 或者 硫脲。三组分高岭土催化Biginelli的机理(使用尿素 和 硫脲)和Biginelli喜欢(使用 2-氨基苯并噻唑)反应已被调查。这是我们首次使用1 H NMR,13 C NMR和ESI-质谱表征来分离和表征关键中间体。机理研究强烈建议使用亚胺3和Knoevenagel型中间体4作为关键中间体。该反应简单,清洁并且在数分钟内获得了良好的产率。
Lewis Acid Catalyzed Synthesis of 1-Aryl-1,2-dihydro-naphtho[1,2-e][1,3]oxazin-3-ones under Solvent Free Conditions: A Mechanistic Approach
作者:Mukul Sharma、Sunny Manohar、Diwan S. Rawat
DOI:10.1002/jhet.825
日期:2012.5
Lewisacidscatalyzed highly efficient one‐pot three component coupling of β‐naphthol, benzaldehydes and urea to produce 1‐aryl‐1,2‐dihydro‐naphtho[1,2‐e][1,3]oxazin‐3‐one derivatives under solvent free conditions is described. Mechanistic studies confirmed that product formation is possible only at very high temperature (140–150°C) and at lower temperature (90–100°C) formation of 14‐aryl‐14H‐dibenzo(a
路易斯酸催化β-萘酚,苯甲醛和尿素的高效一锅三组分偶联,生成1-芳基-1,2-二氢萘并[1,2-e] [1,3]恶嗪-3-酮衍生物描述了在无溶剂条件下。机理的研究证实,产物形成可以仅在非常高的温度(140-150℃),并在较低的温度下(90-100℃)的14 -芳基- 14形成ħ -二苯并(A,j)的观察到的呫吨。在筛选的九种路易斯酸中,碘,P 2 O 5和Yb(OTf)3被发现是该多组分反应最有效的催化剂。
ONE POT PREPARATIONS N,N'-ALKYLIDENE BISAMIDE DERIVATIVES CATALYZED BY NANO-TiCL4.SiO2 WITH ANTIMICROBIAL STUDIES OF SOME PRODUCTS
作者:SOGHRA KHABNADIDEH、KAMIAR ZOMORODIAN、BI BI FATEMEH MIRJALILI、ELHAM IZADI、LEILA ZAMANI
DOI:10.4067/s0717-97072016000300005
日期:——
2 has been introduced to be an extremely efficient catalyst for the preparation of N,N’ -alkylidene bisamides from various aldehydes and amides under mild conditions. We synthesized this solid Lewis acid catalyst by the reaction of nano-SiO 2 and TiCl 4 . The processor was simple and environmentally benign with high to excellent yields. Our method has the advantages of high yields, simple methodology
Organocatalytic Application of Ionic Liquids: [bmim][MeSO4] as a Recyclable Organocatalyst in the Multicomponent Reaction for the Preparation of Dihydropyrimidinones and -thiones
substitution in the latter. The ionic liquid can be recovered and reused for five consecutive reactions without significant loss of catalytic efficiency. The applicability of the methodology for large-scale reaction highlights its potential for bulk synthesis. ionic liquid - organocatalyst - multicomponent reaction - dihydropyrimidinone - dihydropyrimidinethione