19611-17-7Relevant academic research and scientific papers
Reaction of arylethanals with boron tribromide
Dupont, Romain,Cotelle, Philippe
, p. 8457 - 8460 (1998)
Treatment of arylethanals 1 with boron tribromide give 2- phenylnaphthalenes 2 or 1,2,9,10-tetrahydro-1,9- epoxydibenzo[a,e]cyclooctenes 3 by a tandem aldol condensation- intramolecular Friedel-Crafts cyclization or a condensation at the O-position followed by a double Friedel-Crafts alkylation respectively. In all cases, a total demethylation of the methoxy groups occurs.
Electrochemical Aminoxyl-Mediated Oxidation of Primary Alcohols in Lignin to Carboxylic Acids: Polymer Modification and Depolymerization
Rafiee, Mohammad,Alherech, Manar,Karlen, Steven D.,Stahl, Shannon S.
, p. 15266 - 15276 (2019/10/19)
An electrochemical process has been developed for chemoselective oxidation of primary alcohols in lignin to the corresponding carboxylic acids. The electrochemical oxidation reactions proceed under mildly basic conditions and employ 2,2,6,6-tetramethyl-1-piperidine N-oxyl (TEMPO) and 4-acetamidoO (ACT) as catalytic mediators. Lignin model compounds and related alcohols are used to conduct structure-reactivity studies that provide insights into the origin of the reaction selectivity. The method is applied to the oxidation of lignin extracted from poplar wood chips via a mild acidolysis method, and the reaction affords a novel polyelectrolyte material. Gel permeation chromatography data for the oxidized lignin shows that this material has a molecular weight and molecular weight distribution very similar to that of the extracted lignin, but notable differences are also evident. Base titration reveals a significant increase in the acid content, and the oxidized lignin has much higher water solubility relative to the extracted lignin. Treatment of the oxidized lignin under acidic conditions results in depolymerization of the material into characterized aromatic monomers in nearly 30 wt% yield.
A tandem annulation with a [1,3]-hydride transfer as the key step leading to isochromans
Wang, Yingwei,Li, Guangxun,Liu, Hongxin,Tang, Zhuo,Cao, Yuan,Zhao, Gang
supporting information, p. 10652 - 10655 (2017/10/06)
An unprecedented method that enables the direct coupling of an α-C-H bond in alcohols with 2-arylacetaldehydes through a [1,3]-hydride transfer ([1,3]-HT) of oxocarbenium ions catalyzed by a Lewis acid has been developed. The redox neutral preparation of
Tandem catalytic depolymerization of lignin by water-tolerant Lewis acids and rhodium complexes
Jastrzebski, Robin,Constant, Sandra,Lancefield, Christopher S.,Westwood, Nicholas J.,Weckhuysen, Bert M.,Bruijnincx, Pieter C.A.
, p. 2074 - 2079 (2017/07/25)
Lignin is an attractive renewable feedstock for aromatic bulk and fine chemicals production, provided that suitable depolymerization procedures are developed. Here, we describe a tandem catalysis strategy for ether linkage cleavage within lignin, involving ether hydrolysis by water-tolerant Lewis acids followed by aldehyde decarbonylation by a Rh complex. In situ decarbonylation of the reactive aldehydes limits loss of monomers by recondensation, a major issue in acid-catalyzed lignin depolymerization. Rate of hydrolysis and decarbonylation were matched using lignin model compounds, allowing the method to be successfully applied to softwood, hardwood, and herbaceous dioxasolv lignins, as well as poplar sawdust, to give the anticipated decarbonylation products and, rather surprisingly, 4-(1-propenyl)phenols. Promisingly, product selectivity can be tuned by variation of the Lewis-acid strength and lignin source.
Synthesis of 2-phenylnaphthalenes from styryl-2-methoxybenzenes
Mudududdla, Ramesh,Sharma, Rohit,Abbat, Sheenu,Bharatam, Prasad V.,Vishwakarma, Ram A.,Bharate, Sandip B.
supporting information, p. 12076 - 12079 (2015/02/19)
A new simple and efficient method for the synthesis of 2-phenylnaphthalenes from electron-rich 1-styryl-2-methoxybenzenes has been described. The reaction proceeds via TFA catalyzed C-C bond cleavage followed by intermolecular [4+2]-Diels-Alder cycloaddition of an in situ formed styrenyl trifluoroacetate intermediate. The quantum chemical calculations identified the transition state for the cycloaddition reaction and helped in tracing the reaction mechanism. The method has been efficiently utilized for synthesis of the phenanthrene skeleton and a naphthalene-based potent and selective ER-β agonist. This journal is
Substituent effects on the iodine-catalyzed thermal cyclization of 3,4-diphenylbuta-1,3-dienyl isocyanates: Mechanistic studies
Chuang, Ta-Hsien,Chang, Wei-Yu,Li, Chien-Fu,Wen, Yu-Chia,Tsai, Chia-Chen
experimental part, p. 9678 - 9686 (2012/01/05)
The thermal cyclization of 3,4-diphenylbuta-1,3-dienyl isocyanates 1, generated in situ from the corresponding azides, was investigated using iodine as a catalyst. Diphenylpyridinones 2, phenylnaphthalenes 3, and indenes 4 were produced via intramolecular ring closure. The nature of the substituents on the phenyl rings was found to be crucial to the distribution of cyclized products 2 - 4. The mechanism of the reaction is also discussed.
New 2-arylnaphthalenediols and triol inhibitors of HIV-1 integrase - Discovery of a new polyhydroxylated antiviral agent
Maurin, Cedric,Lion, Cedric,Bailly, Fabrice,Touati, Nadia,Vezin, Herve,Mbemba, Gladys,Mouscadet, Jean Franois,Debyser, Zeger,Witvrouw, Myriam,Cotelle, Philippe
scheme or table, p. 5194 - 5201 (2010/09/05)
A series of 13 hydroxylated 2-arylnaphthalenes have been synthesized and evaluated as HIV-1 integrase inhibitors. 7-(3,4,5-Trihydroxyphenyl)naphthalene- 1,2,3-triol 1c revealed chemical instability upon storage, leading to the isolation of a dimer 5c which was also tested. In the 2-arylnaphthalene series, all compounds were active against HIV-1 IN with IC50's within the 1-10 μM range, except for 1c and 5c which displayed submicromolar activity. Antiviral activity against HIV-1 replication was measured on 1b-c and 5c. Amongst the tested molecules, only 5c was found to present antiviral properties with a low cytotoxicity on two different cell lines.
Facile access to methoxylated 2-phenylnaphthalenes and epoxydibenzocyclooctenes
Maurin, Cédric,Bailly, Fabrice,Cotelle, Philippe
, p. 7054 - 7058 (2007/10/03)
Methoxylated phenylethanals were treated with concentrated hydrochloric acid in 1,4-dioxane to give methoxylated 2-phenylnaphthalenes or 1,2,9,10-tetrahydro-1,9-epoxydibenzo[a,e]cyclooctenes. Yields in 2-phenylnaphthalenes were quite good and 1,2,9,10-tetrahydro-1,9-epoxydibenzo[a, e]cyclooctenes could be easily isolated. 2-Phenylnaphthalenes were obtained by a tandem aldol condensation-intramolecular Friedel-Crafts cyclisation and 1,2,9,10-tetrahydro-1,9-epoxydibenzo[a,e]cyclooctenes by a O-condensation followed by a double intramolecular Friedel-Crafts alkylation.
Reaction of 1-(3,4-Dimethoxybenzylidene)-6,7-dimethoxyisochroman-3-one with Lithium Aluminium Hydride: Formation of 1-(3,4-Dimethoxybenzylidene)-6,7-dimethoxyisochroman
Dominguez, E.,Iriondo, C.,Laborra, C.,Lopez, P.,Martinez, J.,Zamora, F.
, p. 549 - 551 (2007/10/02)
Evidence is presented to indicate that the reductive reaction of the isochromanone derivative 1 by means of lithium aluminium hydride (LAH), yielded the isochroman 2 together with small amounts of naphthalene derivatives.All new compounds have been identi
