- Superoxide Oxidation: A Novel Route to Aromatic 1,2-Dicarboxylic Acids
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Potassium superoxide in aprotic media, in the presence of 18-crown-6 ether, effects a novel and mild oxidative cleavage of quinones, cyclic alcohols, and ketones fused to various aromatic hydrocarbons.Aromatic 1,2-dicarboxylic acids are obtained as major products, with highest yields in dimethylformamide, under oxygen or air.For example, the yield of pyrene-1,2-dicarboxylic acid is 82percent from 9,10-dihydrobenzopyren-7(8H)-one and 88percent from benzopyrene-7,8-dione.Minor side products include aromatic tetrones and 3-(2-carboxyaryl)propionic or 3-(2-carboxyaryl)propenoic acid, which provide mechanistic insights.
- Sotiriou, Chariklia,Lee, Wenni,Giese, Roger W.
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Read Online
- PROCESSES FOR THE PREPARATION OF ORTHO-ALLYLATED HYDROXY ARYL COMPOUNDS
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The present application describes process for preparing an ortho-allylated hydroxy aryl compounds such as compounds of Formula (I) by reacting an allylic alcohol with a hydroxy aryl compound in the presence of aluminum compound selected from alumina and aluminum alkoxides and in a non-protic solvent wherein at least one carbon atom ortho to the hydroxy group in the hydroxy aryl compound is unsubstituted. The present application also includes compounds of Formula (I).
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Paragraph 00338-00341
(2021/12/08)
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- Oxime-derived palladacycle Immobilized in an Ionic Liquid Brush as an Efficient and Reusable Catalyst for Mozoroki-Heck Reaction in Neat Water
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An efficient and reusable heterogeneous catalyst with oxime-derived palladacycle immobilized in an ionic liquid brush has been synthesized and an environmentally-friendly procedure have been developed for coupling aryl iodides and bromides with acrylic acid. These reactions were conducted in neat water under aerobic conditions with water-insoluble or even solid aryl halides and they proceeded smoothly and cleanly without any organic co-solvent or other additives. The ionic liquid brush could be easily recovered and reused at least five times without significant loss of activity. The protocol has the advantages of excellent yields, environmental friendliness, and catalyst recyclability.
- Wang, Rong,Li, Shan,Li, Jing,Wei, Junfa
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- Synthesis of o-Carboxyarylacrylic Acids by Room Temperature Oxidative Cleavage of Hydroxynaphthalenes and Higher Aromatics with Oxone
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A simple procedure for the synthesis of a variety of o-carboxyarylacrylic acids has been developed with Oxone (2KHSO5·KHSO4·K2SO4); the oxidation reaction involves the stirring of methoxy/hydroxy-substituted naphthalenes, phenanthrenes, anthracenes, etc. with Oxone in an acetonitrile-water mixture (1:1, v/v) at rt. Mechanistically, the reaction proceeds via initial oxidation of naphthalene to o-quinone, which undergoes cleavage to the corresponding o-carboxyarylacrylic acid. The higher aromatics are found to yield carboxymethyl lactones derived from the initially formed o-carboxyarylacrylic acids.
- Parida, Keshaba Nanda,Moorthy, Jarugu Narasimha
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p. 8354 - 8360
(2015/09/01)
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- IBS-catalyzed regioselective oxidation of phenols to 1,2-quinones with oxone
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We have developed the first example of hypervalent iodine(V)-catalyzed regioselective oxidation of phenols to o-quinones. Various phenols could be oxidized to the corresponding o-quinones in good to excellent yields using catalytic amounts of sodium salts of 2-iodobenzenesulfonic acids (pre-IBSes) and stoichiometric amounts of Oxone as a co-oxidant under mild conditions. The reaction rate of IBS-catalyzed oxidation under nonaqueous conditions was further accelerated in the presence of an inorganic base such as potassium carbonate (K2CO3), a phase transfer catalyst such as tetrabutylammonium hydrogen sulfate (nBu4NHSO4), and a dehydrating agent such as anhydrous sodium sulfate (Na2SO4).
- Uyanik, Muhammet,Mutsuga, Tatsuya,Ishihara, Kazuaki
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scheme or table
p. 8604 - 8616
(2012/10/07)
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- Oxofunctionalized trans-2-carboxycinnamic acids by catalytic domino oxidation of naphthols and hydronaphthoquinones
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(Chemical Equation Presented) The catalytic oxidation of naphthalenes was investigated. Hydrogen peroxide (30% aqueous) was used as an oxygen source, and 2,2′-dinitro-4,4′-ditrifluoromethyldiphenyl diselenide was the oxygen-transfer catalyst. Unsubstitute
- Giurg, Miroslaw,Muchalski, Hubert,Kowal, Ewa
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experimental part
p. 2526 - 2539
(2012/08/07)
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- Oxidation of benzyl alcohols, benzyl halides, and alkylbenzenes with oxone
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Oxidation of benzyl alcohols, benzyl halides, and alkylbenzenes to their corresponding oxidation products has been shown to be accomplished directly with oxone. The methodology that involves mere stirring/heating of the reactants and oxone in acetonitrile/water (1:1, v/v) is simple and practical, but is limited to substrates that do not contain sensitive functionalities and heteroaromatic rings.
- Parida, Keshaba Nanda,Jhulki, Samik,Mandal, Susovan,Moorthy, Jarugu Narasimha
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p. 9763 - 9768,6
(2020/08/20)
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- Tandem reduction + cyclization of ortho-substituted cinnamic esters
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Conjugate reduction of ortho-substituted cinnamic esters by Stryker's reagent to form copper enolates, followed by intramolecular aldol-type cyclization, successfully generated indane and tetralin rings in one pot efficiently. This tandem reaction is generally diastereoselective and provides good yields.
- Sass, Daiane Cristina,De Lucca Jr., Emílio Carlos,Da Silva Barbosa, Jader,De Oliveira, Kleber Thiago,Constantino, Mauricio Gomes
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scheme or table
p. 5371 - 5374
(2011/10/31)
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- Hydroperoxide oxidation of different organic compounds catalyzed by silica-supported selenenamide
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The recoverable heterogeneous silica-supported catalyst selenenamide 2 was prepared by the coupling of 3-aminopropylsilicate (4) with 2-chloroselenobenzoyl chloride (6). Its catalytic activity was demonstrated in tert-butyl hydroperoxide oxidation of aldehydes 8 to carboxylic acids 9 and benzylamines 17 to nitriles 18. Moreover, it was employed for hydrogen peroxide oxidation of azomethine compounds such as tosylhydrazones 10, oximes 13 and N,N-dimethylhydrazones 16 to parent ketones 12, arenecarboxylic acids 11 and 15, their methyl esters 14 and nitriles 18 depending on the substrate used and the reaction conditions. The catalyst was simply recovered by filtration and could be reused.
- Giurg,Brzaszcz,Mlochowski
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p. 417 - 428
(2007/10/03)
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- A mild and selective method for the hydrolysis of esters with trimethyltin hydroxide
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Mild, selective, and efficient: A new method that involves the use of trimethyltin hydroxide for the hydrolysis of specific ester groups allows chemists to steer clear of unwanted elimination reactions and epimerizations. For example, the conversion of ester 1 into carboxylic acid 2 takes place under mild conditions, with nearly complete retention of stereochemical integrity. 1,2-DCE = 1,2-dichloroethane.
- Nicolaou,Estrada, Anthony A.,Zak, Mark,Lee, Sang Hyup,Safina, Brian S.
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p. 1378 - 1382
(2007/10/03)
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- Hydrogen peroxide oxidation of naphthalene derivatives catalyzed by poly (bis-1,2-diphenylene) diselenide
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Oxidation of 1- and 2-substituted naphthalenes (1) with 30% hydrogen peroxide in the presence of poly(bis-1,2-diphenylene) diselenide (PPDS) has been investigated. Depending on the substrate used trans-2-carboxycinnamic acid (2), and its isomer, (1-oxo-1,3-dihydroisobenzofuran-1-yl)acetic acid (3) or 2-naphthoic acid (4b) was a major product. Oxidation of hydroxynaphthalenes 1b and 1c is a convenient way to obtain trans-2-carboxy cinnamic acid (2) in almost quantitative yield. The mechanism of the reaction is postulated.
- Giurg,Syper,Mlochowski
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p. 231 - 238
(2007/10/03)
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- Hemirubin: An Intramolecularly Hydrogen-Bonded Analogue for One-Half Bilirubin
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A model for one-half bilirubin, the neurotoxic yellow-orange pigment of jaundice, 9-[2-(2-carboxyethyl)benzyl]-2,3,7,8-tetramethyl-l,10-dihydrodipyrrin (1, hemirubin) was synthesized following SnCl4-catalyzed Friedel-Crafts acylation at C(9) of
- Chen, Qingqi,Lightner, David A.
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p. 2665 - 2675
(2007/10/03)
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- Oxidation of arenes to para-quinones with hydrogen peroxide catalyzed by hexafluoroacetone hydrate
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Various aromatic hydrocarbons were oxidized with aqueous hydrogen peroxide in the presence of hexafluoroacetone hydrate as catalyst to give para-quinones and/or the ring cleavage oxidation products. The regioselective oxidation of 2-methylnaphthalene to 2-methyl-1,4-naphthoquinone (vitamin K3) was studied in detail.
- Adam,Ganeshpure
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p. 280 - 282
(2007/10/02)
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- Synthesis of substituted cinnamic acids and cinnamonitriles via palladium catalyzed coupling reactions of aryl halides with acrylic acid and acrylonitrile in aqueous media
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The palladium-catalysed coupling reactions of aryl halides with acrylic acid and acrylonitrile in the presence of a base (NaHCO3 or K2CO3) in water provide a novel and efficient and very simple method for the synthesis of substituted cinnamic acids and cinnamonitriles in high yields.NaHCO3 or K2CO3 effectively acts as a base in the reaction at elevated temperature (80-100 deg C).The reaction can be carried out with higher velocity and at low temperature (50-60 deg C), using CH3COOK as a base.
- Bumagin, N. A.,More, P. G.,Beletskaya, I. P.
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p. 397 - 402
(2007/10/02)
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- Synthesis of 3-Carboxyisocoumarins: Wittig Reactions of Phthalaldehydic Acid
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Wittig reaction of phthalaldehydic acid with Ph3P=CHCOOEt and Ph3P=C(Br)COOEt provides the phthalides 1 and 6, 7 and 9 respectively.Phthalides (1) and (6) on hydrolysis furnish the ortho-carboxycinnamic acids (3) and (4).However, attempted thermal cyclisa
- Narasimhan, N. S.,Kusurkar, S. S.
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p. 345 - 348
(2007/10/02)
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