Xi:Irritant;
118-91-2Relevant articles and documents
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.
Atomically Dispersed Co Clusters Anchored on N-doped Carbon Nanotubes for Efficient Dehydrogenation of Alcohols and Subsequent Conversion to Carboxylic Acids
Dong, Zhengping,Fang, Jian,Li, Boyang,Xu, Dan,Zhang, Fengwei,Zhao, Hong,Zhu, Hanghang
, p. 4536 - 4545 (2021/09/22)
The catalytic dehydrogenation of readily available alcohols to high value-added carbonyl compounds is a research hotspot with scientific significance. Most of the current research about this reaction is performed with noble metal-based homogeneous catalysts of high price and poor reusability. Herein, highly dispersed Co-cluster-decorated N-doped carbon nanotubes (Co/N-CNTs) were fabricated via a facile strategy and used for the dehydrogenation of alcohols with high efficiency. Various characterization techniques confirmed the presence of metallic Co clusters with almost atomic dispersion, and the N-doped carbon supports also enhanced the catalytic activity of Co clusters in the dehydrogenation reaction. Aldehydes as dehydrogenation products were further transformed in situ to carboxylic acids through a Cannizzaro-type pathway under alkaline conditions. The reaction pathway of the dehydrogenation of alcohols was clearly confirmed by theoretical calculations. This work should provide an effective and simple approach for the accurate design and synthesis of small Co-clusters catalysts for the efficient dehydrogenation-based transformation of alcohols to carboxylic acids under mild reaction conditions.
