Xi:Irritant;
118-91-2Relevant academic research and scientific papers
TiO2-mediated photomineralization of 2-chlorobiphenyl: The role of O2
Wang, Yongbing,Hong, Chia-Swee
, p. 2791 - 2797 (2000)
Photocatalytic mineralization of 2-chlorobiphenyl (2-CB) in aqueous TiO2 suspensions was conducted under four different oxygen partial pressures (Po2) in closed reactors. The observed O2 adsorption equilibrium constant in TiO2 aqueous suspension was 0.88 (kPa)-1 based on the Langmuir-Hinshelwood rate function. Apart from the conventional electron-scavenging function, the dissolved oxygen was critical for the degradation of the hydroxyl intermediates, i.e., 2-chlorobiphenyl-ols and biphenyl-2-ol, which are potentially toxic. Degradation of 2-CB in the irradiated H2O2 aqueous solutions under two different Po2 was also studied for comparison. For UV/H2O2, Po2 does not affect the removal of 2-CB, while reducing the Po2 from 21 to 2 kPa resulted in 35% less CO2 formation after 5 h irradiation. The similar O2-dependent destruction of the hydroxyl intermediates was also observed in the UV/H2O2 system. We propose that molecular O2 acts as a key reactant following the attack of a second ·OH radical during the ring opening in the degradation of the hydroxyl byproducts. Copyright (C) 2000 Elsevier Science Ltd.
Oxidation of aromatic aldehydes with potassium bromate-bromide reagent and an acidic catalyst
Sharma,Robert, Alice R.
, p. 3251 - 3254 (2013)
We report herein an easy oxidation procedure for converting aromatic aldehydes to aromatic carboxylic acids by use of a combination of commercially and readily available potassium bromate with potassium bromide in the presence of hydrochloric acid catalyst.
Bismuth(III)-catalyzed oxidative cleavage of aryl epoxides: substituent effects on the kinetics of the oxidation reaction
Boisselier, Veronique Le,Dunach, Elisabet,Postel, Michele
, p. 119 - 124 (1994)
Bismuth(III)mandelate catalyzes the oxidative C-C bond cleavage of a series of styrene epoxides in DMSO, to the corresponding aryl carboxylic acids.The reaction is accelerated in the presence of electron-donating groups substituting the phenyl ring.A good Hammet correlation of log kobs versus ? has been obtained, with a ρ of -1.08.Key words: Bismuth; Aryl epeoxide cleavage; Oxidation; Substituent effects; Bi(III) catalysis; Hammet correlation
Chemiluminescence from arylcarbene oxidation: phenylchlorocarbene and (2-chlorophenyl)carbene
Sander, Wolfram W.
, p. 637 - 646 (1987)
Chemiluminescence is observed in the thermal reaction of phenylchlorocarbene or (2-chloro-phenyl)carbene and O2, matrix-isolated in Ar.The chemiluminescence spectra closely match the phosphorescence of the corresponding carbonyl compounds.The reactivity of both carbenes towards O2 is very different.Singlet carbene phenylchlorocarbene reacts thermally only slowly with O2 up to 60 K.The oxidation products phenylchloroformate, benzoyl chloride and O(3P) are mainly formed photochemically on irradiation of the diazirine precursor.Triplet carbene (2-chlorophenyl)carbene reacts readily with O2 at cryogenic temperatures to give mostly 2-chlorobenzaldehyde-O-oxide.The carbonyl-O-oxide is photochemically easily cleaved to give 2-chlorobenzaldehyde and O(3P).The reaction step leading to carbonyl compounds in their excited states is in both carbene oxidations the recombination of the free carbene and O(3P).
Supported ruthenium hydride catalysts for direct conversion of alcohols to carboxylic acids using styrene oxide as oxidant
Ghafouri, Moloud,Moghadam, Majid,Mehrani, Kheirollah,Daneshvar, Anahita
, (2018)
In the present work, the ability of two ruthenium hydride catalysts supported on multiwall carbon nanotubes, [Ru–H@EDT–MWCNT], and gold nanoparticles cored triazine dendrimer, [Ru–H@AuNPs–TD], in the direct conversion of alcohols to carboxylic acids via transfer hydrogenation using styrene oxide as oxidant is reported. Different alcohols were successfully converted to their corresponding carboxylic acids. The results showed that these two heterogeneous catalysts are more efficient than the homogeneous counterpart. In addition, the catalysts were reused several times.
SELECTIVE REMOVAL OF ORTHO HALOGENS BY A DIORGANOLANTHANOID
Deacon, G.B.,MacKinnon, P.I.
, p. 783 - 784 (1984)
Reaction of halogenobenzoic acids with bis(pentafluorophenyl)ytterbium(II) in tetrahydrofuran results in selective removal of ortho halogen substituents.
COBALT CARBONYL-CATALYZED DOUBLE-CARBONYLATION OF O-HALOGENATED BENZOIC ACIDS UNDER PHOTOSTIMULATION
Kashimura, Tsugunori,,Kudo, Kiyoshi,Mori, Sadayuki,Sugita, Nobuyuki
, p. 483 - 486 (1986)
Cobalt carbonyl-catalyzed double-carbonylation of o-dihalobenzenes and o-halogenated benzoic acids, affording phthalonic acid, was observed in aqueous sodium hydroxide under photostimulation.
Reductions and radical cyclizations of aryl and alkyl bromides mediated by NaBH4 in aqueous base
Rai, Roopa,Collum, David B.
, p. 6221 - 6224 (1994)
Reductions and free radical cyclizations of alkyl- and aryl bromides are effected in aqueous base by NaBH4 in conjunction with a base-soluble dialkyltin(IV) reagent and 4,4'-azobis(4-cyanovaleric acid) (ACVA). The aryl bromides reduce at lower rates under tin-free conditions using simply NaBH4-ACVA.
Direct oxidation of alcohols to carboxylic acids over ruthenium hydride catalyst with diphenyl sulfoxide oxidant
Barati, Behjat,Moghadam, Majid,Rahmati, Abbas,Mirkhani, Valiollah,Tangestaninejad, Shahram,Mohammadpoor-Baltork, Iraj
, p. 114 - 117 (2013)
In the present work, a new method for the synthesis of carboxylic acids over ruthenium hydride catalyst is reported. Direct oxidation of alcohols to their corresponding carboxylic acids with diphenyl sulfoxide oxidant over RuHCl(CO)(PPh3)3 catalyst was investigated. Mild reaction conditions, short reaction times and excellent yields make this method as an appealing way for preparation of carboxylic acids.
Alkali-modified heterogeneous Pd-catalyzed synthesis of acids, amides and esters from aryl halides using formic acid as the CO precursor
Fapojuwo, Dele Peter,Maqunga, Nomathamsanqa Prudence,Meijboom, Reinout,Mogudi, Batsile M.,Molokoane, Pule Petrus,Onisuru, Oluwatayo Racheal,Oseghale, Charles O.
, p. 26937 - 26948 (2021/08/17)
To establish an environmentally friendly green chemical process, we minimized and resolved a significant proportion of waste and hazards associated with conventional organic acids and molecular gases, such as carbon monoxide (CO). Herein, we report a facile and milder reaction procedure, using low temperatures/pressures and shorter reaction time for the carboxyl- and carbonylation of diverse arrays of aryl halides over a newly developed cationic Lewis-acid promoted Pd/Co3O4catalyst. Furthermore, the reaction proceeded in the absence of acid co-catalysts, and anhydrides for CO release. Catalyst reusability was achievedviascalable, safer, and practical reactions that provided moderate to high yields, paving the way for developing a novel environmentally benign method for synthesizing carboxylic acids, amides, and esters.
