Cobalt and Manganese Salts of p -Aminobenzoic Acid Supported on Silica Gel: A Versatile Catalyst for Oxidation by Molecular Oxygen
作者:Mohammed M. Hashemi、Yusef Ahmadibeni
DOI:10.1007/s00706-002-0534-3
日期:2003.2.1
A 1:1 molar ratio of the cobalt and manganese salts of p -amino benzoic acid supported on silica gel is an effective catalyst for the oxidation of various organic compounds in reasonable yields using molecular oxygen. The catalyst can be reused several times.
Silica-supported ceric ammonium nitrate (CAN): a simple, mild and solid-supported reagent for quickest oxidative aromatization of Hantzsch 1,4-dihydropyridines
An efficient and environmentally benign methodology for the oxidative aromatization of 1,4-dihydropyridines to their corresponding pyridine derivatives is developed. The oxidative aromatization of 1,4-dihydropyridines was explored using silica-supported ceric ammonium nitrate as catalyst in CH3CN with or without sonication at room temperature. This supported catalyst acts as a more efficient oxidising
Ring-contraction of hantzsch esters and their derivatives to pyrroles <i>via</i> electrochemical extrusion of ethyl acetate out of aromatic rings
作者:Xu Liu、Chang Liu、Xu Cheng
DOI:10.1039/d1gc00487e
日期:——
ring-contraction of HEs and theirs pyridinederivatives is developed to obtain polysubstituted pyrroles. This process provides an orthogonal utilization of Hantzsch esters for the well-documented application as side chain or hydrogen donors. The formal transformation shows an extrusion of ethyl acetate out of the pyridine ring in a single step. In addition to the novel transformation, we also discovered the Lewis
Aromatization of Hantzsch 1,4-Dihydropyridines with I2-MeOH
作者:Jhillu S. Yadav、Basi V. Subba Reddy、Gowravaram Sabitha、Garudammagari S. Kiran Kumar Reddy
DOI:10.1055/s-2000-7613
日期:——
4-Alkyl or aryl substituted Hantzsch1,4-dihydropyridines are aromatized to the corresponding pyridines in high yields by iodine in refluxing methanol. The method tolerates several substituents such as alkyl, benzyl, aryl and heterocyclic groups present in the 4-position of pyridines.
Iodoxybenzoic Acid (IBX): An Efficient and Novel Oxidizing Agent for the Aromatization of 1,4-Dihydropyridines
作者:J. S. Yadav、B. V. Reddy、A. K. Basak、G. Baishya、A. Venkat Narsaiah
DOI:10.1055/s-2005-918519
日期:——
Hantzsch 1,4-dihydropyridines undergo smooth aromatization catalyzed by iodoxybenzoic acid (IBX) to afford the corresponding pyridine derivatives in high yields. All the reactions were carried out in DMSO solvent at 80-85 °C for a period of two to four hours to complete conversion of the substrates.