Oxidation Of Primary Aliphatic Alcohols Research Articles

Kinetics and correlation analysis of reactivity in the oxidation of aliphatic primary alcohols by isoquinolinium dichromate in non-aqueous medium

Mild oxidation in dimethyl sulfoxide (DMSO) medium by isoquinolinium dichromate (IQDC) of aliphatic primary alcohols produces corresponding carbonyl compounds. A Michaelis-Menten kind kinetics noticed as for alcohols while unit dependency on rate observed as for IQDC. At non-identical temperatures the formation constants and the rates of decomposition of alcohol-IQDC complexes have been evaluated. Thermodynamic parameters and activation parameters for formation of the complex and break down of the complexes have been determined respectively. The oxidation process accelerates with increase in proton concentration. An α-C-H bond fisson in the rate-controlling step suggested by the deuterium isotope effect. For oxidation of ethanol, kH/kD = 5.82 at 293 K, was observed. The oxidation rates have been evaluated in 19 organic solvents and greater role of solvating power of the cation is observed. Depended on the kinetic parameters, solvent effect analysis and the outcome of thermodynamic parameters, a mechanism in which rate-controlling break down of the complex is suggested, to give the resulting product through hydride-ion transfer with a cyclic transition state.

Single-Pot Synthesis of Alkyl-Substituted Quinolines and Indoles via Photoinduced Oxidation of Primary Alcohols

Single-pot synthesis of alkyl-substituted quinolines and indoles has been performed via photoinduced oxidation of primary aliphatic alcohols (C2–C5) and condensation of the aldehydes (products of the alcohols oxidation) with aniline under the action of iron-containing catalysts and inorganic oxidants. The synthesis was the most efficient in the presence of FeCl3·6H2O as catalyst and 10% aqueous solution of NaOCl as oxidant with irradiation by Hg lamp. The synthesis mechanism through photoinduced oxidation of primary aliphatic alcohol has been suggested.

Correlation analysis of reactivity in the oxidation of aliphatic primary alcohols by imidazolium dichromate

Correlation analysis of reactivity in the oxidation of aliphatic primary alcohols by imidazolium dichromate

Bio-based aliphatic primary amines from alcohols through the ‘Nitrile route’ towards non-isocyanate polyurethanes

Bio-based primary amines obtained from the corresponding alcohols via nitrile intermediates and their subsequent polymerizations with cyclic carbonates are described. Nitrile compounds were synthesized under mild aerobic oxidation of primary aliphatic alcohols. CuI, bipyridine and TEMPO were used as a catalytic system, in the presence of aqueous ammonia and O2. A series of bio-sourced alcohols were successfully oxidized into nitriles using this catalytic system. The so-formed bio-based dinitriles were subsequently reduced into primary diamines under H2 in the presence of Ni Raney. The latter were polymerized with fatty acid-based bis-cyclic carbonates for the design of fully bio-based poly(hydroxyurethane)s.

Kinetics and Mechanism of Oxidation of Aliphatic Primary Alcohols with 1-Chlorobenzimidazole in Aqueous Acetic Acid Medium

Abstract The kinetics of oxidation of a few aliphatic primary alcohols with 1-chlorobenzimidazole (CBI) was studied in aqueous acetic acid medium. The reactions were found to be first order each with respect to the concentrations of CBI and alcohol. The added HClO4 increases the rate and the order in HClO4 was found to be fractional. The reactions were catalyzed by NaCl and fractional order dependence was observed. The ionic strength had negligible influence on the rate. The reaction rates increase with decrease in dielectric constant of acetic acid. Addition of benzimidazole, one of the products does not affect the rate. Effect of temperature on the reaction rates was studied at different temperatures and the various activation and thermodynamic parameters were evaluated. The rate constants show good correlation with Taft–Pavelich Dual substituent parameter model (DSP). Product analysis shows the formation of aldehydes as major products of oxidation of aliphatic primary alcohols. CBIH+ has been postulated as the reactive oxidizing species. A mechanism involving a proton transfer by water molecule has been proposed.

A Simple Procedure for the Oxidation of Alcohols Using [Bis(acetoxy)iodo]benzene and a Catalytic Amount of Bromide Ions in Ethyl Acetate

Primary and secondary benzylic alcohols and secondary aliphatic alcohols were oxidized to the corresponding aldehydes and ketones by using [bis(acetoxy)iodo]benzene (BAIB) and a catalytic amount of bromide ions, from tetrabutylammonium bromide or KBr, in ethyl acetate. The catalytic role of the bromide ions was also highlighted in the oxidation of primary aliphatic alcohols and secondary allylic alcohols carried out in the presence of 1 mol% TEMPO.

Kinetics and mechanism of the selective oxidation of primary aliphatic alcohols under phase transfer catalysis

Article history: Received March 28, 2013 Received in Revised form August 28, 2013 Accepted 27 November 2013 Available online 28 November 2013 Kinetics of the oxidation of primary aliphatic alcohols has been carried out using phase transferred monochromate in benzene. Tetrabutylammonium bromide (TBAB) and tetrabutylphosphonium bromide (TBPB) are used as phase transfer catalysts (PT catalyst). The reaction shows first order dependence on both [alcohol] and [monochromate ion]. The oxidation leads to the formation of corresponding aldehyde and no traces of carboxylic acid has been detected. The reaction mixture failed to induce the polymerization of added acrylonitrile which rules out the presence radical intermediates in the reaction. Various thermodynamic parameters have been evaluated and a suitable mechanism has been proposed. © 2014 Growing Science Ltd. All rights reserved.

Aerobic oxidation of primary aliphatic alcohols over bismuth oxide supported platinum catalysts in water

Catalytic oxidation of non-activated aliphatic alcohols with molecular oxygen is rather challenging, especially in an aqueous medium in the absence of an additional base. Bismuth is usually used as a promoter of platinum-based catalysts. In this work, bismuth oxide was explored as a support, and Pt0 nanoparticles supported on bismuth oxide (Pt/Bi2O3) exhibited high activity for aerobic oxidation of n-butanol using water as a solvent in the absence of an additional base under optimized conditions. Besides n-butanol, liquid primary aliphatic alcohols with low solubility in water could also be smoothly oxidized into the corresponding carbonyl compounds with molecular oxygen. Pt/Bi2O3 reduced by H2 at about 200 °C showed the highest activity for aerobic oxidation of n-butanol. At this temperature, platinum oxide was reduced to Pt0 and bismuth oxide could be reduced partially which might change the surface property of bismuth oxide.

Efficient Dimeric Esterification of Alcohols with NBS in Water Using L-Proline as Catalyst

The L-proline-catalyzed oxidation of aliphatic primary alcohols with N-bromosuccimide (NBS) in water at room temperature to afford the corresponding dimeric esters in good to excellent yields was described. This pathway of dimeric esterification was proved to be very simple and environmentally friendly.

Efficient CuCl-Catalyzed Selective and Direct Oxidation of β- and γ-Substituted Aliphatic Primary Alcohols to Carboxylic Acids

A new procedure for the selective and direct oxidation of aliphatic primary alcohols having substitution at β- and γ-positions to corresponding carboxylic acids was developed using a catalytic amount of ligand and additive-free CuCl with anhydrous t BuOOH in acetonitrile solvent under very mild reaction conditions. This procedure is very simple and mild and works efficiently without any additives at room temperature.

Aerobic Oxidation of Primary Aliphatic Alcohols to Aldehydes Catalyzed by a Palladium(II) Polyoxometalate Catalyst

AbstractA hexadecyltrimethylammonium salt of a “sandwich” type polyoxometalate has been used as a ligand to attach a palladium(II) center. This Pd‐POM compound was an active catalyst for the fast aerobic oxidation of alcohols. The unique property of this catalyst is its significant preference for the oxidation of primary versus secondary aliphatic alcohols. Since no kinetic isotope effect was observed for the dehydrogenation step, this may be the result of the intrinsically higher probability for oxidation of primary alcohols attenuated by steric factors as borne out by the higher reactivity of 1‐octanol versus 2‐ethyl‐1‐hexanol. The reaction is highly selective to aldehyde with little formation of carboxylic acid; autooxidation is inhibited. No base is required to activate the alcohol. The fast reactions appear to be related to the electron‐acceptor nature of the polyoxometalate ligand that may also facilitate alcohol dehydrogenation in the absence of base.

Oxidation of aliphatic primary alcohols by morpholinium chlorochromate : A kinetic and mechanistic approach

The oxidation of nine aliphatic primary alcohols by morpholinium chlorochromate (MCC) in dimethylsulfoxide leads to the transformation of alcohols to the corresponding aldehydes. The reaction is first order with respect to both MCC and the alcohol both. The reaction is catalysed by hydrogen ions. The hydrogen-ion dependence has the form: k obs = a + b[H + ]. The oxidation of [1,1- 2 H 2 ]ethanol (MeCD 2 OH) exhibits a substantial primary kinetic isotope effect. The reaction has been studied in nineteen different organic solvents. The solvent effect was analysed using Taft's and Swain's multiparametric equations. The rate of oxidation is susceptible to both polar and steric effects of the substituents. A suitable mechanism has been proposed.

Efficient, recoverable, copper-catalyzed aerobic oxidation of alcohols under FBS and thermomorphic mode

A series of fluorinated bipyridine derivatives, (4,4′-bis(R fCH 2OCH 2)-2,2′-bpy) {R f = n-C 8F 17 ( 1a), n-C 9F 19 ( 1b), n-C 10F 21 ( 1c), n-C 11F 23 ( 1d)} have been successfully synthesized using 4,4′-bis(bromomethylene)-2,2′-bpy and fluorinated alkoxides. Bpy 1a– d have been characterized by multi-nuclei ( 1H, 19F, and 13C) NMR, GC/MS and FTIR. The Cu complexes 2a– d could be generated in situ by stirring ligands 1a– d with CuBr·Me 2S at room temperature, respectively. The 3-component systems 3c– d, CuBr·Me 2S/Bpy ( 1c– d)/2,2,6,6-Tetramethylpiperidine 1-oxyl (TEMPO), were successfully used to the aerobic oxidation of alcohols under the fluorous biphasic system (FBS). The resulting products from FBS could be easily recovered by two phase separation with high yields up to 8 runs (>90%). In order to avoid using the expensive fluorous solvents, systems 3a– d, CuBr·Me 2S/Bpy ( 1a– d)/TEMPO, were also successfully shown to catalyze the aerobic alcohol oxidation under the thermomorphic condition (in C 6H 5Cl), and the yields of oxidation of 4-nitrobenzyl alcohol were close to 100% even after 8 runs. In particular, 3a was most effective under the thermomorphic mode in the chemoselectivity of aerobic oxidation of aliphatic primary alcohols to aldehydes without any overoxidized acids.

Oxidation catalysis of microporous metal carboxylate complexes

Abstract A microporous copper(II) carboxylate complex, copper(II) trans -1,4-cyclohexanedicarboxylate [Cu 2 II,II (OOCC 6 H 10 COO) 2 ]·H 2 O ( 1 ) can act as a biomimetic heterogeneous catalyst for selective oxidation of various alcohols with H 2 O 2 . A green-colored active intermediate, H 2 [Cu 2 II,II (OOCC 6 H 10 COO) 2 (O 2 )]·H 2 O ( 2 ), observed in the reaction of 1 with 20-fold excess H 2 O 2 in acetonitrile was characterized by elemental analysis, TG/DTA, magnetic susceptibility, FT-IR, diffuse reflectance (DR) UV–vis, electron paramagnetic resonance (EPR), X-ray powder diffraction (XRPD), resonance Raman, BET surface area, pore size distribution, and nitrogen occlusion measurements. The molecular structure of 2 was determined from XRPD data and refined by the Rietveld method. The microporous structure of 2 was constructed by intermolecular bridging of μ-1,2- trans Cu–OO–Cu species between two-dimensional [Cu 2 (O 2 CC 6 H 10 CO 2 )] layers, which was the first example of microporous copper(II) peroxo complex for heterogeneous oxidation catalysis. Moreover, a microporous ruthenium(II,III) complex having porphyrin [Ru II,III 2 (H 2 TCPP)]BF 4 ( 3 ) (H 2 TCPP = 4,4′,4″,4‴-(21H,23H-porphine-5,10,15,20-tetrayl)tetrakis benzoic acid) particularly exhibited an effective catalytic performance for the heterogeneous oxidation of primary aliphatic alcohols with dioxygen and air without any additives at room temperature. The reaction pathway included the formation of an Ru–oxygen radical intermediate, which was due to the high affinity of diruthenium(II,III) sites for dioxygen.

Kinetics and mechanism of the oxidation of aliphatic primary alcohols by benzyltriethylammonium chlorochromate

The oxidation of nine aliphatic primary alcohols by benzyltriethylammonium chlorochromate (BTEACC) in dimethylsulfoxide (DMSO) leads to the formation of corresponding aldehydes. The reaction is first order with respect to both BTEACC and the alcohol. The reaction is catalysed by hydrogen ions. The hydrogen-ion dependence has the form: k obs = a + b [H + ]. The oxidation of [1,1- 2 H 2 ]ethanol (MeCD 2 OH) exhibits a substantial primary kinetic isotope effect. The reaction has been studied in nineteen different organic solvents. The solvent effect was analysed using Taft's and Swain's multiparametric equations. The rate of oxidation is susceptible to both polar and steric effects of the substituents. A suitable mechanism has been proposed.

Catalytic oxidation of alcohols with polymer-supported ruthenium complex under mild conditions

Polymer-supported ruthenium-containing complex PS–Phen–Ru was synthesized (where PS = chloromethyl polystyrene resin, Phen = 1,10-phenanthroline) and was characterized by FT-IR, ICP, and XPS. The supported complex was used to catalyze the oxidation of primary aliphatic alcohols as well as aromatic alcohols in the presence of iodosylbenzene. The oxidations were carried out in acetonitrile solution, affording the corresponding aldehydes or ketones in high substrate conversion and high selectivities under mild reaction conditions. The catalyst can be easily prepared and can be recycled.

Oxoperoxo molybdenum(vi) and tungsten(vi) and oxodiperoxo molybdate(vi) and tungstate(vi) complexes with 8-quinolinol: synthesis, structure and catalytic activity

A solution obtained by dissolving MoO3 in a moderate excess of H2O2 reacts with 8-quinolinol (QOH) to give [MoO(O2)(QO)2] (1), but, when the same reaction is conducted with a large excess of H2O2, an anionic complex is formed, which reacts with PPh4Cl to give the corresponding salt [MoO(O2)2(QO)][PPh4] (2·PPh4). Freshly prepared WO3 behaves the same way and, depending on the amount of H2O2 used, as above, produces either [WO(O2)(QO)2] (3) or [WO(O2)2(QO)][PPh4] (4·PPh4), respectively. Crystallographic analyses reveal the coordination geometries around the metal center in these complexes to be distorted pentagonal bipyramids. These compounds show interesting catalytic properties in the oxidation of alcohols using H2O2 as the terminal oxidant. In the case of aromatics, including benzylic and cinnamylic alcohols, the oxidation occurs selectively, affording aldehydes or ketones with reasonably high turnover numbers. Taking benzyl alcohol as a representative case, a probable mechanism of the alcohol-to-aldehyde conversion mediated by the prepared catalysts is suggested. The oxidation of aliphatic primary alcohols, under the same conditions, does not show the above selectivity: the reaction yields the corresponding aldehydes as well as carboxylic acids. The work was also extended to study the catalytic activity towards the oxidation of phenol and various sulfides and amines using the same oxidants.

Efficient, copper-catalyzed, aerobic oxidation of primary alcohols.

An additive is the key to success: Catalytic amounts of N-methylimidazole are crucial for the aerobic oxidation of primary aliphatic alcohols in the presence of CuCl, 1,10-phenanthroline (phen), and di-tert-butyl azodicarboxylate (DBAD). This reaction, under neutral conditions, yields the aldehydes quantitatively and selectively without overoxidation to the carboxylic acids.

Kinetics and mechanism of oxidation of aliphatic primary alcohols by quinolinium bromochromate

Oxidation of nine aliphatic primary alcohols by quinolinium bromochromate (QBC) in dimethylsulphoxide leads to the formation of the corresponding aldehydes. The reaction is first order with respect to both QBC and the alcohol. The reaction is catalysed by hydrogen ions. The hydrogen-ion dependence has the form:k obs = a + b[H+]. The oxidation of [1,1-2H2]ethanol (MeCD2OH) exhibits a substantial primary kinetic isotope effect. The reaction has been studied in nineteen different organic solvents. The solvent effect was analysed using Taft’s and Swain’s multiparametric equations. The rate of oxidation is susceptible to both polar and steric effects of the substituents. A suitable mechanism has been proposed.

Tetrazolium-dye-linked alcohol dehydrogenase of the methylotrophic actinomycete Amycolatopsis methanolica is a three-component complex.

Tetrazolium-dye-linked alcohol dehydrogenase (TD-ADH) of Amycolatopsis methanolica could be resolved into three protein components, which have been purified. Each of the components has the ability to reconstitute TD-ADH activity when combined with the other two. Component 1 is identical to the previously characterized methanol:N,N'-dimethyl-4-nitrosoaniline oxidoreductase (MNO), a decameric protein with 50-kDa subunits, each carrying a tightly bound NADPH. Component 2 is a high molecular mass (> 640 kDa) protein with subunits of 44 kDa and 72 kDa, and which possesses a low tetrazolium-dye-linked NADH dehydrogenase activity. The protein contains a yellow chromophore of unknown identity. Component 3 is a low molecular mass (15 kDa) protein containing a 5'-deazaflavin and at least one other low-molecular-mass compound with properties similar, but not identical, to those of nicotinamide coenzymes. The results suggest that alcohol oxidation by the TD-ADH complex is carried out by component 1 (MNO), after which transfer of the reducing equivalents (mediated by component 3) occurs to component 2, which (in vitro) is linked to the tetrazolium dye. Fractionation of A. methanolica extracts showed that most of the 5'-deazaflavin was present in component 3. Other gram-positive bacteria having a TD-ADH complex also produced 5'-deazaflavin. It is concluded that oxidation of primary aliphatic alcohols by A. methanolica, and probably also by other gram-positive bacteria containing MNO or TD-ADH, proceeds via TD-ADH. The likeliness of 5'-deazaflavin participation in this process is discussed.