A novel protocol for selective synthesis of monoclinic zirconia nanoparticles as a heterogeneous catalyst for condensation of 1,2-diamines with 1,2-dicarbonyl compounds
A rapid, efficient, and reliable catalyst-free procedure for the synthesis of quinoxaline derivatives in glycerol under focused microwave irradiation was developed. The reaction proceeded in glycerol without any catalyst making this methodology valuable from both economic and environmental viewpoints.
Microwave-assisted Solvent-free Synthesis and in Vitro Antibacterial Screening of Quinoxalines and Pyrido[2, 3b]pyrazines
作者:J. Jesús Morales-Castellanos、Karina Ramírez-Hernández、Nancy S. Gómez-Flores、Oscar R. Rodas-Suárez、Javier Peralta-Cruz
DOI:10.3390/molecules17055164
日期:——
We report herein the microwaveassistedsynthesis, without solvents and catalysts, of 6-substituted quinoxalines and 7-substituted pyrido[2,3b]pyrazines. The compounds were obtained in good yields and short reaction times using the mentioned procedure and two new structures are reported. A complete 1H- and 13C-NMR assignment was performed using 1D and 2D-NMR. Additionally, an in vitro screening was
Crystalline nanobelts of α-MoO3 have been obtained successfully using novel and safe agents through a simple and safe solâgel method (polymerizingâcomplexing) and characterized by XRD, FT-IR, Raman spectroscopies, high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and the temperature programmed desorption (TPD) of ammonia. An orthorhombic lattice system for nano-MoO3 was established. The HRTEM images showed that the nanobelt morphology of α-MoO3 mostly ranged from 20â70 nm in width and 200â400 nm in length. The ammonia TPD profile demonstrated strong acidic sites. The spectral and analysis data confirmed the effectiveness of the method for the preparation of α-MoO3 nanobelts by prevention of grain growth or agglomeration of the particles. The nanostructured MoO3 exhibited a high efficiency in catalyzing the condensation reaction of various 1,2-diamine and carbonyl compounds for synthesis of heterocyclic compounds. The recovery of the title heterogenous nanocatalyst was easy and efficient and its catalytic activity was strikingly different from the bulk material.
A zirconium Schiff base complex immobilized on starch-coated maghemite nanoparticles catalyzes heterogeneous condensation of 1,2-diamines with 1,2-dicarbonyl compounds
作者:Maasoumeh Jafarpour、Abdolreza Rezaeifard
DOI:10.1007/s11243-015-0012-5
日期:2016.3
A magnetically separable zirconium Schiff base nanocatalyst was synthesized under ultrasonic agitation. TEM images revealed a uniform spherical particle shape with average size of 10–14 nm for the as-prepared catalyst. The catalytic performance of ZrOL2@SMNP in the heterogeneous condensation of various 1,2-diamines and 1,2-dicarbonyls for the synthesis of heterocyclic compounds in ethanol has been explored.
Heterocyclizations in the pyrido[2,3-<i>b</i>]pyrazine series
作者:Y. Blache、A. Gueiffier、O. Chavignon、J. C. Teulade、J. C. Milhavet、H. Viols、J. P. Chapat、G. Dauphin
DOI:10.1002/jhet.5570310127
日期:1994.1
the results of heterocyclizations in the pyrido[2,3-b]pyrazine series to give the pyrido[2,3-e] or [3,2-e]pyrrolo[1,2-a]pyrazine. The Clauson-Kaas reaction on 2,3-diaminopyridine is investigated; regioselectivity on the 3-amino group is shown by 1H- and 13C-nmr. Synthesis and reactivity of the original pyrazino[2,3-g]indolizine series is also reported.
在本文中,我们报告了吡啶并[2,3- b ]吡嗪系列中杂环化的结果,从而得到了吡啶并[2,3- e ]或[3,2- e ]吡咯并[1,2- a ]吡嗪。研究了2,3-二氨基吡啶上的克劳森-卡斯反应。3-氨基上的区域选择性由1 H-和13 C-nmr表示。还报道了原始吡嗪并[2,3- g ]吲哚嗪系列的合成和反应性。