- A green approach for aerobic oxidation of benzylic alcohols catalysed by CuI-Y zeolite/TEMPO in ethanol without additional additives
-
An efficient and green protocol for aerobic oxidation of benzylic alcohols in ethanol using CuI-Y zeolite catalysts assisted by TEMPO (TEMPO = 2,2,6,6-tetramethyl-1-piperidine-N-oxyl) as the radical co-catalyst in the presence of atmospheric air under mild conditions is reported. The CuI-Y zeolite prepared via ion exchange between CuCl and HY zeolite was fully characterized by a variety of spectroscopic techniques including XRD, XPS, SEM, EDX and HRTEM. The incorporation of Cu(i) into the 3D-framework of the zeolite rendered the catalyst with good durability. The results of repetitive runs revealed that in the first three runs, there was hardly a decline in activity and a more substantial decrease in yield was observed afterwards, while the selectivity remained almost unchanged. The loss in activity was attributed to both the formation of CuO and the bleaching of copper into the liquid phase during the catalysis, of which the formation of CuO was believed to be the major contributor since the bleaching loss for each run was negligible (2%). In this catalytic system, except TEMPO, no other additives were needed, either a base or a ligand, which was essential in some reported catalytic systems for the oxidation of alcohols. The aerobic oxidation proceeded under mild conditions (60 °C, and 18 hours) to quantitatively and selectively convert a wide range of benzylic alcohols to corresponding aldehydes, which shows great potential in developing green and environmentally benign catalysts for aerobic oxidation of alcohols. The system demonstrated excellent tolerance against electron-withdrawing groups on the phenyl ring of the alcohols and showed sensitivity to steric hindrance of the substrates, which is due to the confinement of the pores of the zeolite in which the oxidation occurred. Based on the mechanism reported in the literature for homogenous oxidation, a mechanism was analogously proposed for the aerobic oxidation of benzylic alcohols catalysed by this Cu(i)-containing zeolite catalyst. This journal is
- Senthilkumar, Samuthirarajan,Zhong, Wei,Natarajan, Mookan,Lu, Chunxin,Xu, Binyu,Liu, Xiaoming
-
p. 705 - 713
(2021/01/25)
-
- Synthesis and Immobilization of Metal Nanoparticles Using Photoactive Polymer-Decorated Zeolite L Crystals and Their Application in Catalysis
-
A facile route to generate Au and Pd nanoparticles (NPs) on zeolite L crystals decorated with photoactive polymer brushes is described. The polymers used in this approach serve a dual role: Upon irradiation with UV light, they release highly reducing ketyl radicals in a Norrish-Type-I reaction. These radicals serve as one electron donors to reduce metal salts to the corresponding metal NPs. At the same time the polymer shell stabilizes the in situ generated metal NPs. It is shown that the zeolite-polymer-NP composites can be used as recyclable catalysts for the oxidation of benzylic alcohols to aldehydes and the stereoselective semihydrogenation of alkynes to Z-alkenes. The polymer shell in these hybrid catalysts protects the NPs from aggregation and also alters their catalytic properties. (Figure presented.).
- Wissing, Maren,Niehues, Maximilian,Ravoo, Bart Jan,Studer, Armido
-
supporting information
p. 2245 - 2253
(2020/05/05)
-
- Production and testing of technical catalysts based on MnO2 for the abatement of aromatic volatile compounds at the laboratory and pilot plant scales
-
Shaping is a crucial step to produce technical catalysts that remains as some sort of dark art for catalytic researchers in academia. This contribution discusses aspects concerning the fabrication of technical catalysts based on MnO2 powders ai
- Baldovino-Medrano, Víctor Gabriel,Kartheuser, Beno?t,Gaigneaux, Eric M.
-
-
- Simple formylation of aromatic compounds using a sodium formate/triphenylphosphine ditriflate system
-
A new procedure was developed for formylation of arenes to produce aromatic aldehydes using a sodium formate/triphenylphosphine ditriflate system in ethanol at room temperature in good yields. The simplicity of the procedure, short reaction times, and mild reaction conditions are the other advantages of this metal- and carbon monoxide-free protocol.
- Khodaei, Mohammad M.,Alizadeh, Abdolhamid,Hezarkhani, Hadis Afshar
-
supporting information
p. 840 - 843
(2017/06/13)
-
- Novel oxidative aromatic alkene cleavage with sodium nitrite under mild conditions
-
We have developed a simple and practical process for the oxidation of aromatic alkene to the corresponding carbonyl compounds using NaNO2 as an oxidant. The practical utility of this oxidative process has been demonstrated in the gram-scale oxidation of 1-(tert-butyl)-4-vinylbenzene.
- Yin, Bo,Peng, Xiangjun,Huang, Panpan,Huang, Qing,Liu, Liangxian
-
supporting information
p. 2189 - 2194
(2017/11/15)
-
- A Copper-Benzotriazole-Based Coordination Polymer Catalyzes the Efficient One-Pot Synthesis of (N′-Substituted)-hydrazo-4-aryl-1,4-dihydropyridines from Azines
-
A series of new (N′-substituted)-hydrazo-4-aryl-1,4-dihydropyridines was successfully synthesized via a facile one-pot catalytic pathway utilizing azines and propiolate esters as starting materials and a one-dimensional copper benzotriazole-based coordination polymer as catalyst. In the absence of catalyst, the corresponding 5-substituted 4,5-dihydropyrazoles were formed in moderate to high yields. Fine-tuning of the catalysts allowed us to gain more insights regarding the plausible reaction mechanism. (Figure presented.).
- Kallitsakis, Michael,Loukopoulos, Edward,Abdul-Sada, Alaa,Tizzard, Graham J.,Coles, Simon J.,Kostakis, George E.,Lykakis, Ioannis N.
-
supporting information
p. 138 - 145
(2017/01/14)
-
- Oxygenation of Methylarenes to Benzaldehyde Derivatives by a Polyoxometalate Mediated Electron Transfer-Oxygen Transfer Reaction in Aqueous Sulfuric Acid
-
The synthesis of benzaldehyde derivatives by oxygenation of methylarenes is of significant conceptual and practical interest because these compounds are important chemical intermediates whose synthesis is still carried out by nonsustainable methods with very low atom economy and formation of copious amounts of waste. Now an oxygenation reaction with a 100% theoretical atom economy using a polyoxometalate oxygen donor has been found. The product yield is typically above 95% with no "overoxidation" to benzoic acids; H2 is released by electrolysis, enabling additional reaction cycles. An electrocatalytic cycle is also feasible. This reaction is possible through the use of an aqueous sulfuric acid solvent, in an aqueous biphasic reaction mode that also allows simple catalyst recycling and recovery. The solvent plays a key role in the reaction mechanism by protonating the polyoxometalate thereby enabling the activation of the methylarenes by an electron transfer process. After additional proton transfer and oxygen transfer steps, benzylic alcohols are formed that further react by an electron transfer-proton transfer sequence forming benzaldehyde derivatives. (Chemical Equation Presented).
- Sarma, Bidyut Bikash,Efremenko, Irena,Neumann, Ronny
-
p. 5916 - 5922
(2015/05/27)
-
- Formylation of electron-rich aromatic rings mediated by dichloromethyl methyl ether and TiCl4: Scope and limitations
-
Here the aromatic formylation mediated by TiCl4 and dichloromethyl methyl ether previously described by our group has been explored for a wide range of aromatic rings, including phenols, methoxy- and methylbenzenes, as an excellent way to produce aromatic aldehydes. Here we determine that the regioselectivity of this process is highly promoted by the coordination between the atoms present in the aromatic moiety and those in the metal core.
- Ramos-Tomillero, Iván,Paradís-Bas, Marta,De Pinho Ribeiro Moreira, Ibério,Bofill, Josep María,Nicolás, Ernesto,Albericio, Fernando
-
supporting information
p. 5409 - 5422
(2015/05/13)
-
- An improved protocol for the oxidative cleavage of alkynes, alkenes, and diols with recyclable Ru/C
-
Efficient synthesis of carboxylic acids from alkynes; aldehydes from alkenes and diols employing Ru/C-based recyclable catalytic system is reported with good to excellent yields. Georg Thieme Verlag Stuttgart.
- Vijay Kumar,Prakash Reddy,Sridhar,Srinivas,Rama Rao
-
experimental part
p. 739 - 742
(2009/07/18)
-
- Orthoamides, LXVII [1]. Bis(diformylamino)methane - A new efficient formylating reagent for aromatic compounds
-
Formaldehyde reacts with diformamide (10) to give N-(hydroxymethyl) diformamide (11), which upon treatment with thionylchloride yields N-(chlormethyl)diformamide (12) together with small amounts of oxydimethylenebis(diformamide) (13). Various diformylamine derivatives, such as diformylaminomethyl formiate (14), diformylaminomethylisothiocyanate (15) and the N-diformylaminomethylated guanidinium salt 16, can be prepared from 12. Bis(diformylamino) methane (7) can be obtained by the reaction of sodium diformamide (8) with either 1-(chloromethyl)pyridinium chloride (9) or N-(chloromethyl)diformamide (12) in acetonitrile. The action of tris(chloromethyl) amine (18) on sodium diformamide (8) affords tris(diformylaminomethyl)amine (19). The constitution of the compounds 7,11 and 19 was confirmed by crystal structure determination. The nature of the products from the reactions of aromatic compounds with 12 depends on the Lewis acid which is used as activator. Thus the N-benzylformamides 20a, b can be obtained from toluene and mesitylene and 12/BF3-ether, whereas 1,2,4- trimethoxybenzene is formylated by 12/AlCl3 to give the aldehyde 22. Interestingly enough, a novel and efficient formylating reagent resulted from these investigations: bis(diformylamino)methane (7), which can be activated by Lewis acids, e. g. AlCl3. The scope of this procedure is comparable with that of the Olah-formylation method (formylfluoride/BF3).
- Kantlehner, Willi,Anders, Ernst,Mezger, Jochen,Stoyanov, Edmont V.,Kre?, Ralf,Wermann, Kurt,Frey, Wolfgang,G?rls, Helmar
-
experimental part
p. 395 - 406
(2009/01/31)
-
- Oxidation of alcohols and vic-diols with H2O2 by using catalytic amounts of N-methylpyrrolidin-2-one hydrotribromide
-
A variety of secondary alcohols, 1,2-diols and primary alcohols were selectively oxidized in excellent yields to their corresponding ketones, 1,2-diketones and aldehydes with aqueous 30 % hydrogen peroxide in refluxing acetonitrile in the presence of catalytic amounts of N-methylpyrrolidin-2-one hydrotribromide (MPHT). Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Joseph, Jomy K.,Jain, Suman L.,Sain, Bir
-
p. 590 - 594
(2007/10/03)
-
- Orthoamide, LX [1]. N,N,N',N'-Tetraformylhydrazine- a Formylation Agent for Aromatic Compounds of Wide Scope
-
The reagent system formed from N,N,N',N'-tetraformylhydrazine (3) and aluminum chloride allows the formylation of aromatic compounds. The scope of the method is comparable with the Olah formylation and the Gross-Rieche procedure, since benzene and fluorobenzene can be formylated. Two formyl groups are transferred from 3 to the aromatic nuclei when a molar ratio 4:1:4 (aluminum chloride/3/aromatic compound) is chosen.
- Kantlehner, Willi,Haug, Erwin,Scherr, Oliver,Stoyanov, Edmont V.,Mezger, Jochen,Ziegler, Georg
-
p. 355 - 365
(2007/10/03)
-
- Benzylic biooxidation of various toluenes to aldehydes by peroxidase
-
A catalytic method is described for the oxidation of toluene and substituted derivatives to the corresponding benzaldehydes by hydrogen peroxide, using peroxidase. In most cases the respective benzoic acid was produced as a byproduct. The reaction proceeds under mild conditions in an aqueous medium.
- Russ, Rainer,Zelinski, Thomas,Anke, Timm
-
p. 791 - 793
(2007/10/03)
-
- An easy and fast method for oxidative deprotection of trimethylsilyl ethers, tetrahydropyranyl ethers, and ethylene acetals with KMnO4 supported on alumina under solvent-free conditions
-
A manipulatively simple and rapid method for oxidation deprotection of trimethylsilyl ethers, tetrahydropyranyl ethers and deprotection of ethylene acetals to afford carbonyl compounds under solvent-free conditions in the presence or absence of alumina with potassium permanganate.
- Hajipour,Mallakpour,Baltork,Backnezhad
-
p. 771 - 779
(2007/10/03)
-
- Orthoamides. LIII. A New Synthesis for Aromatic Aldehydes of Wide Scope
-
Diformamide (1) reacts with activated aromatic compounds like toluene, anisole, m-xylene, 1,2-dimethoxybenzene in the presence of AlCl3 to give N-(diarylmethyl)-formamides 2a-d, the corresponding aromatic aldehydes 3-6 are formed as by-products in low yields. From N,N-dimethylaniline and 1/AlCl3 the triphenylmethane derivative 7 can be obtained. The reaction of anisole with N-methyl-diformamide (9) affords the formamide 10. The mixture of formamide, P4O10 and AlCl3 reveals to be a reagent which is capable to formylate toluene and anisole, resp. Triformamide (14)/AlCl3 is an effective formylating system which allows the preparation of aromatic aldehydes (e.g. 3,4,17-32) from the corresponding aromatic hydrocarbons. Aluminiumchloride can be replaced by borontrichloride. The yields of the formylation reactions depend strongly from the reaction conditions (molar ratio: aromatic hydrocarbon/ AlCl3/14; solvent, reaction temperature). The scope of the reaction covers nearly complete those of the Gattermann-Koch-, Gattermann- and Vilsmeier-Haack-reaction.
- Kantlehner, Willi,Vettel, Markus,Gissel, Alexander,Haug, Erwin,Ziegler, Georg,Ciesielski, Michael,Scherr, Oliver,Haas, Richard
-
p. 297 - 310
(2007/10/03)
-
- Oxidation of 1,2,4- and 1,3,5-Trimethylbenzenes with Cerium(IV) Ions in Perchloric Acid Solutions
-
The reaction stoichiometry and the influence of certain reagents on the rate of reduction of cerium(IV) ions with 1,2,4- and 1,3,5-trimethylbenzenes are examined. Permanently formed intermediates are identified, and conditions for their isolation are developed. The most probable oxidation mechanisms are proposed.
- Deka,Dziegiec
-
p. 1896 - 1901
(2007/10/03)
-
- SYNTHESIS OF A NEW SERIES OF OO-tert-BUTYL ALKYLBENZYL (NAPHTHYLMETHYL)PEROXYCARBONATES
-
A series of OO-tert-butyl monoperoxycarbonates, differing in the structure of the alkyl aromatic fragments, were obtained from arylmethyl chloroformates and sodium tert-butyl hydroperoxide.Their thermal dissociation at 110-140 deg C takes place by a monomolecular mechanism with no contribution from chain reactions.The increase in the decomposition rate constant with increase in the polarity of the solvent indicates some polarization of the peroxide bond in the transition state while the homolytic character of its cleavage is retained.
- Etlis, I. V.,Fomin, V. A.,Nozrina, F. D.,Kurskii, Yu. A.,Shmuilovich, S. M.
-
p. 820 - 825
(2007/10/02)
-
- THERMAL DISSOCIATION OF DI(ALKYLBENZYL)NAPHTHYL>PEROXYDICARBONATES IN RELATION TO THE STRUCTURE OF THE ALKYL AROMATIC FRAGMENTS
-
The kinetics of the thermolysis of di peroxydicarbonates at 40-70 deg C in organic solvents were investigated, the effectiveness of escape of the free radicals from the solvent "cage" was studied, and the final products from thermal dissociation of the peroxydicarbonates were investigated.A scheme was formulated for the thermolysis of peroxides, explaining the relation between the homolysis rate of the O-O group and the reactivity of the obtained free radicals in relation to the structure of the alkylbenzyl fragments in the symmetrical and unsymmetrical peroxydicarbonates.
- Fomin, V. A.,Etlis, I. V.,Kurskii, Yu. A.,Nozrina, F. D.,Chervyakova, G. N.,Shmuilovich, S. M.
-
p. 811 - 819
(2007/10/02)
-
- Oxidative Dealkylation of 4-Substituted N,N-Dialkylanilines with Molecular Oxygen in the Presence of Acetic Anhydride Promoted by Cobalt(II) or Copper(I) Chloride
-
The reaction of 4-substituted N,N-dimethylanilines 1a-d with acetic anhydride 5 proceeded efficiently in the presence of a catalytic amount of cobalt(II) or copper(I) chloride under oxygen to give the corresponding N-methylacetanilides 2a-d along with N-methylformanilides 3a-d.The reaction of N-alkyl-N-methyl-p-toluidines 1f-h with cobalt chloride revealed that the order of reactivity of the N-substituents follows the sequence allyl > benzyl >/= methyl > ethyl, while in the case of copper chloride the order was benzyl > allyl > methyl > ethyl.Aldehydes 18a-e and phenylglyoxylic acid derivatives 18f and 18g were obtained in fair to good yield from the reaction of n-substituted N-ethyl-p-toluidines 17a-g.
- Murata, Satoru,Suzuki, Kaoru,Tamatani, Akira,Miura, Masahiro,Nomura, Masakatsu
-
p. 1387 - 1392
(2007/10/02)
-
- Formylation of Aromatic Compounds with CO in HSO3F-SbF5 under Atmospheric Pressure
-
The formylation of aromatic compounds such as benzene, toluene, xylenes, mesitylene, indan, tetralin, fluorobenzene, chlorobenzene, and bromobenzene was carried out in HSO3F-SbF5 under atmospheric CO pressure at 0 deg C.In HSO3F-SbF5, both formylation and sulfonation took place to give formyl and sulfonyl compounds.In the case of alkylbenzenes, including toluene, xylenes, mesitylene, and tetralin, formylalkylbenzenesulfonyl fluorides, new compounds, were obtained by a one-pot reaction as well as alkylbenzaldehydes, alkylbenzenesulfonyl fluorides, and bis(alkylphenyl) sulfones.The direct introduction of a formyl and sulfonyl group was achieved in alkylbenzenes.The reaction path of the new compounds is a two-step reaction comprised of formylation as the first step and sulfonation as the second step.The product composition was strongly dependent on the acid strength of the HSO3F-SbF5 systems.The formyl compounds became predominant with increasing acidity of the HSO3F-SbF5 system.On the other hand, only sulfonyl compounds were produced when the acidity of the HSO3F-SbF5 system was low.
- Tanaka, Mutsuo,Iyoda, Jun,Souma, Yoshie
-
p. 2677 - 2680
(2007/10/02)
-
- Process for nucleophilic fluoroalkylation of aldehydes
-
Aryl difluoromethyl sulfone adds to alkehydes under phase transfer conditions to give novel substituted alcohols of the general formula wherein R is an aryl, cycloaliphatic, sec- or tert-aliphatic, or heterocyclic group and Ar is an aryl group. The substituted alcohols of formula I are of particular utility as intermediates in the synthesis of a variety of useful end products. For example, the products of formula I may be utilized in desulfonylation reactions, oxidation reactions and fluorination reactions.
- -
-
-
- Ortho Metalation Directed by α-Amino Alkoxides
-
The addition of aromatic aldehydes to certain lithium dialkylamides in benzene or tetrahydrofuran gave α-amino alkoxides which were ortho lithiated with excess n-butyllithium.Subsequent alkylation and hydrolysis provided ortho-substituted aromatic aldehydes via a one-pot reaction.The ortho metalation of α-amino alkoxides derived from 1- and 2-naphthaldehyde and various substituted benzaldehydes was examined.When N,N,N'-trimethylethylenediamine was used as the amine component of the α-amino alkoxide, metalation could be carried out at lower temperatures.This rate increase is due to an intramolecular TMEDA-like assisted metalation.The synthetic utility of this ortho metalation, including how varying the amine component of the α-amino alkoxide affects the regiochemistry and metalation rate, is discussed.
- Comins, Daniel L.,Brown, Jack D.
-
p. 1078 - 1083
(2007/10/02)
-
- Formylation and Acylation Reactions Catalysed by Trifluoromethanesulphonic Acid
-
Regioselective formylation of toluene, m- and p-xylene, and mesitylene has been achieved by carbonylation in trifluoromethanesulphonic acid at CO pressures of 90-125 atm.In the case of cumene, the formylation reaction is in competition with disproportionation to form di- and tri-isopropylbenzenes, leading to a complex product mixture.Slow addition of cyclohexene or cyclopentene to a mixture of benzene and CF3SO3H under a high CO pressure affords 4-cyclohexylbenzaldehyde and 4-cyclopentylbenzaldehyde in 34percent and 33percent yieds, respectively, while 2-methylbut-1-ene gives 2,2,3-trimethylindanone (39percent) under similar conditions.When cyclohexene is mixed with the acid under carbon monoxide (120 atm) before addition of benzene the major products are cyclohexyl phenyl ketone and cyclohexenyl cyclohexyl ketones.
- Booth, Brian L.,El-Fekky, Teymour A.,Noori, Ghazi F. M.
-
p. 181 - 186
(2007/10/02)
-
