Phosphine free Mn-complex catalysed dehydrogenative C–C and C–heteroatom bond formation: a sustainable approach to synthesize quinoxaline, pyrazine, benzothiazole and quinoline derivatives
作者:Kalicharan Das、Avijit Mondal、Dipankar Srimani
DOI:10.1039/c8cc05877f
日期:——
Herein the first sustainable synthesis of quinoxalines, pyrazines and benzothiazoles catalysed by a phosphine free Mn(I) complex via acceptorless dehydrogenative coupling (ADC) is reported. This method is also applied successfully to synthesize quinolines via the dehydrogenation (removal of H2) and condensation (removal of H2O) reaction between 2-aminobenzyl alcohols and secondary alcohols.
Tandem oxidation processes for the preparation of nitrogen-containing heteroaromatic and heterocyclic compounds
作者:Steven A. Raw、Cecilia D. Wilfred、Richard J. K. Taylor
DOI:10.1039/b315689c
日期:——
alpha-hydroxy ketones undergo manganese dioxide-mediated oxidation followed by in situ trapping with aromatic or aliphatic 1,2-diamines to give quinoxalines or dihydropyrazines, respectively, in a one-pot procedure which avoids the need to isolate the highly reactive dicarbonyl intermediates. The scope and limitations of these procedures are outlined and modifications to this procedure are discussed
Manganese(iv) dioxide-catalyzed synthesis of quinoxalines under microwave irradiation
作者:So Yeon Kim、Kang Hyun Park、Young Keun Chung
DOI:10.1039/b417556e
日期:——
We synthesize quinoxalines, catalyzed by manganese(IV) dioxide, from a variety of α-hydroxyketones followed by trapping with aromatic or aliphatic 1,2-diamines without using a solvent, within one minute under microwave irradiation.
Gas-phase pyrolysis of 2,3-dihydro-1,4-diazepines: involvement of the saturated portion of the ring in chemical reactions and novel cis–trans isomerisation of a fused ring system
作者:Michael J. Ellis、Douglas Lloyd、Hamish McNab、Marion J. Walker
DOI:10.1039/c39950002337
日期:——
Flashvacuumpyrolysis of 2,3-dihydro-1,4-diazepines in the range 450–550 °C involves interaction of the saturated portion of the molecule with the vinamidine system and causes 1,5-hydrogen shifts which have been established by deuterium labelling experiments; at higher temperatures, ring contraction occurs to give pyrazines as major products.
A Phosphine-Free Air-Stable Mn(II)-Catalyst for Sustainable Synthesis of Quinazolin-4(3H)-ones, Quinolines, and Quinoxalines in Water
作者:Sucheta Mondal、Subhajit Chakraborty、Subhankar Khanra、Santana Chakraborty、Shrestha Pal、Paula Brandão、Nanda D. Paul
DOI:10.1021/acs.joc.3c02579
日期:2024.4.19
in water under air following two pathways via the dehydrogenative coupling of alcohols with 2-aminobenzamides and 2-aminobenzonitriles, respectively. 2-Aminobenzyl alcohol and ketones bearing active methylene group were used as coupling partners for synthesizing quinoline derivatives, and various quinoxaline derivatives were prepared by coupling vicinaldiols and 1,2-diamines. In all cases, the reaction
新型无膦、结构明确、水溶性且空气稳定的Mn(II)催化剂[Mn(L)(H 2 O) 2 Cl](Cl)的合成、表征和催化应用[ 1 ]Cl) 具有基于 1,10-菲咯啉的三齿钳配体 2-(1 H-吡唑-1-基)-1,10-菲咯啉 ( L ),用于将醇脱氢官能化成各种N -杂环,例如这里报道了喹唑啉-4(3 H )-酮、喹啉和喹喔啉。通过醇与2-氨基苯甲酰胺和2-氨基苯甲腈的脱氢偶联两种途径,在空气下的水中制备了多种多取代喹唑啉-4(3 H )-酮。以2-氨基苯甲醇和带有活性亚甲基的酮为偶联伙伴合成喹啉衍生物,通过邻位二醇与1,2-二胺偶联制备各种喹喔啉衍生物。在所有情况下,使用我们的 Mn(II)-催化剂 [ 1 ]Cl 在空气中的水中,反应顺利进行,从廉价且易于获得的前体开始,以令人满意的收率提供了所需的N-杂环。这些化合物的克级合成表明了我们的合成策略的工业相关性。进行对照实验以了解和揭示合理的反应机制。