- Synthesis of new Zn (II) complexes for photo decomposition of organic dye pollutants, industrial wastewater and photo-oxidation of methyl arenes under visible-light
-
Synthesis of new Schiff's base Zn-complexes for photo-oxidation of methyl arenes and xylenes are reported under visible light irradiation conditions. All the synthesized new ligands and Zn-complexes are thoroughly characterized with various spectral analyses and confirmed as 1:1 ratio of Zn and ligand with distorted octahedral structure. The bandgap energies of the ligands are higher than its Zn-complexes. These synthesized new Zn(II) complexes are used for the photo-fragmentation of organic dye pollutants, photodegradation of food industrial wastewater and oxidation of methyl arenes which are converted into its respective aldehydes with moderate yields under visible light irradiation. The photooxidation reaction dependency on the intensity of the visible light was also studied. With the increase in the dosage of photocatalyst, the methyl groups are oxidized to get aldehydes and mono acid products, which are also identified from LC-MS data. Finally, [Zn(PPMHT)Cl] is with better efficiency than [Zn(PTHMT)Cl] and [Zn(MIMHPT)Cl] for oxidation of methyl arenes is reported under visible-light-driven conditions.
- Ahemed, Jakeer,Bhongiri, Yadagiri,Chetti, Prabhakar,Gade, Ramesh,Kore, Ranjith,Pasha, Jakeer,Pola, Someshwar,Rao D, Venkateshwar
-
-
- Preparation method for synthesizing aryl aldehyde compounds by reducing aryl secondary amide or aryl secondary amide derivative through phenylsilane
-
The invention provides a preparation method for synthesizing aryl aldehyde compounds by reducing an aryl secondary amide or aryl secondary amide derivative through phenylsilane. In an inert atmosphere, the aryl secondary amide or an aryl secondary amide derivative is used as a raw material, phenylsilane is used as a reducing agent, 1, 4-dioxane or tetrahydrofuran or diethyl ether is used as a solvent, under the action of isopropyl magnesium chloride, a reaction is performed for 12-48 h at 40-70 DEG C, quenching, separating and purification are performed after the reaction is completed, and the aryl aldehyde product is obtained. The whole preparation process realizes one-step conversion from aryl secondary amide to aryl aldehyde, has the advantages of low cost, mild reaction conditions and high reaction yield, and avoids the use of high-temperature harsh conditions and high-cost noble metal catalysts.
- -
-
Paragraph 0062-0066
(2021/11/10)
-
- A Magnetically Recyclable Palladium-Catalyzed Formylation of Aryl Iodides with Formic Acid as CO Source: A Practical Access to Aromatic Aldehydes
-
A magnetically recyclable palladium-catalyzed formylation of aryl iodides under CO gas-free conditions has been developed by using a bidentate phosphine ligand-modified magnetic nanoparticles-anchored- palladium(II) complex [2P-Fe 3O 4@SiO 2-Pd(OAc) 2] as catalyst, yielding a wide variety of aromatic aldehydes in moderate to excellent yields. Here, formic acid was employed as both the CO source and the hydrogen donor with iodine and PPh 3as the activators. This immobilized palladium catalyst can be obtained via a simple preparative procedure and can be facilely recovered simply by using an external magnetic field, and reused at least 9 times without any apparent loss of catalytic activity.
- You, Shengyong,Zhang, Rongli,Cai, Mingzhong
-
supporting information
p. 1962 - 1970
(2021/01/25)
-
- A Remote ‘Imidazole’-Based Ruthenium(II) Para-Cymene Pre-catalyst for the Selective Oxidation Reaction of Alkyl Arenes and Alcohols
-
Herein we disclosed the use of a remote ‘imidazole’-based precatalyst [(para-cymene)RuII(L)Cl]+, C-1 where L=2-(4-substituted-phenyl)-1H-imidazo[4,5-f][1,10] phenanthroline) for the selective oxidation of a variety of alkyl arenes/heteroarenes and alcohols to their corresponding aldehydes or ketones in presence of tert-butyl hydroperoxide (TBHP). The remote ‘imidazole’ moiety present in the complex facilitates the activation of oxidant and subsequent generation of active species via the release of para-cymene from C-1, which in-turn was less effective without the ‘imidazole’ moiety. The mechanistic features of C-1 promoted oxidation of alkyl arenes were also assessed from spectroscopic, kinetic, and few control experiments. The substrate scope for C-1 promoted oxidation reaction was assessed based on the selective oxidation of 27-different alkyl arenes/heteroarenes and 25 different alcohols to their corresponding aldehydes/ketones in moderate to good yields.
- Dutta, Manali,Bania, Kusum K.,Pratihar, Sanjay
-
p. 926 - 932
(2020/03/05)
-
- Selective TEMPO-Oxidation of Alcohols to Aldehydes in Alternative Organic Solvents
-
The TEMPO-catalyzed oxidation of alcohols to aldehydes has emerged to one of the most widely applied methodologies for such transformations. Advantages are the utilization of sodium hypochlorite, a component of household bleach, as an oxidation agent and the use of water as a co-solvent. However, a major drawback of this method is the often occurring strict limitation to use dichloromethane as an organic solvent in a biphasic reaction medium with water. Previous studies show that dichloromethane cannot easily be substituted because a decrease of selectivity or inhibition of the reaction is observed by using alternative organic solvents. Thus, up to now, only a few examples are known in which after a tedious optimization of the reaction dichloromethane could be replaced. In order to overcome the current limitations, we were interested in finding a TEMPO-oxidation method in alternative organic solvents, which is applicable for various alcohol oxidations. As a result, we found a method for N-oxyl radical-catalyzed oxidation using sodium hypochlorite as an oxidation agent in nitriles as an organic solvent component instead of dichloromethane. Besides the oxidation of aromatic primary alcohols also aliphatic primary alcohols, secondary alcohols as well as dialcohols were successfully converted when using this method, showing high selectivity towards the carbonyl compound and low amounts of the acid side-product.
- Hinzmann, Alessa,Stricker, Michael,Busch, Jasmin,Glinski, Sylvia,Oike, Keiko,Gr?ger, Harald
-
p. 2399 - 2408
(2020/04/29)
-
- Photo-Difunctionalization and Photo-Oxidative Cleavage of the C–C Double Bond of Styrenes in the Presence of Nanosized Cadmium Sulfide (CdS) as a Highly Efficient Photo-Induced Reusable Nanocatalyst
-
The synthesis of cyclic dithiocarbonates via photo-difunctionalization of the C–C double bond of styrene and aryl aldehydes via photo-oxidative cleavage of the C–C double bond of styrene was accomplished in the presence of CdS NPs at room temperature in air atmosphere under visible light irradiation without using any external oxidant. Some of the special advantages of these processes are the use of CdS NPs as a simple, accessible, safe, and visible-light-induced reusable catalyst, as well as the use of air as an easily attainable, inexpensive, and harmless oxidant, styrene as a readily accessible substrate, and visible-light as a renewable and safe energy source.
- Firoozi, Somayeh,Hosseini-Sarvari, Mona
-
p. 3834 - 3843
(2020/07/06)
-
- Visible-light-driven photochemical activity of ternary Ag/AgBr/TiO2nanotubes for oxidation C(sp3)-H and C(sp2)-H bonds
-
The Ag/AgBr/TiO2 ternary component nanotube as a heterogeneous photocatalyst was used for the solvent-free oxidation of the benzylic C(sp3)-H bond to the corresponding carbonyl compound or the solvent-controlled selective oxidative cleavage of the CC double bond of styrene to benzaldehyde under visible light at room temperature. A wide variety of carbonyl compounds were successfully synthesized through the developed photocatalytic process. Several advantages such as solvent-free conditions, sans additional oxidant, simple reaction, short reaction time, and easy separation of the product promote the reaction to be green. Moreover, the Ag/AgBr/TiO2 nanotubes could be used several times without reduction in their photocatalytic activity. This journal is
- Hosseini-Sarvari, Mona,Dehghani, Abdulhamid
-
p. 16776 - 16785
(2020/10/27)
-
- UV light promoted 'Metal'/'Additive'-free oxidation of alcohols: Investigating the role of alcohols as electron donors
-
UV light promoted selective oxidation of primary and secondary alcohols has been demonstrated under 'metal-free' and 'additive-free' conditions. Under the optimized conditions, a variety of aromatic, heteroaromatic, and alicyclic alcohols have been examined for their transformations to the corresponding carbonyl compounds. The mechanistic studies emphasize the important role of substrate (alcohol) and solvent (DMSO) in the generation of superoxide radical which is a vital intermediate for the transformation. This study also highlights the role of air as the oxidant in the oxidation process. Further, the practical application of the strategy has also been demonstrated for the oxidation of the alcoholic moiety in cholesterol.
- Walia, Preet Kamal,Sharma, Manik,Kumar, Manoj,Bhalla, Vandana
-
p. 36198 - 36203
(2019/11/20)
-
- Metal-ligand cooperativity in a ruthenium(II) complex of bis-azoaromatic ligand for catalytic dehydrogenation of alcohols
-
Herein a new Ru-phosphine complex (1) with molecular formula [RuL(PPh3)Cl2] is reported where L is a redox active pincer ligand 2,6-bis(phenylazo)pyridine. The isolated complex has been characterized by usual spectroscopic techniques including single crystal X-ray crystallographic analysis. Complex 1 efficiently catalyzes aerobic oxidation of a wide range of primary and secondary benzylic, allylic, heterocyclic, alicyclic alcohols under mild conditions and is found to be superior over several other Ru (0, +2 and +3), Ru-H and Ru-PPh3 catalysts. Mechanistic studies indicate that a transient Ru-H intermediate is formed in the catalytic cycle which gets switched into a Ru-hydrazo intermediate via hydrogen-walking mechanism. The catalyst is regenerated by aerial oxidation producing H2O2 as a by-product.
- Saha, Tanushri,Pramanick, Rajib,Sengupta, Debabrata,Goswami, Sreebrata
-
p. 160 - 166
(2018/09/29)
-
- Oxidative Cleavage of Alkene C=C Bonds Using a Manganese Catalyzed Oxidation with H2O2 Combined with Periodate Oxidation
-
A one-pot multi-step method for the oxidative cleavage of alkenes to aldehydes/ketones under ambient conditions is described as an alternative to ozonolysis. The first step is a highly efficient manganese catalyzed epoxidation/cis-dihydroxylation of alkenes. This step is followed by an Fe(III) assisted ring opening of the epoxide (where necessary) to a 1,2-diol. Carbon–carbon bond cleavage is achieved by treatment of the diol with sodium periodate. The conditions used in each step are not only compatible with the subsequent step(s), but also provide for increased conversion compared to the equivalent reactions carried out on the isolated intermediate compounds. The described procedure allows for carbon–carbon bond cleavage in the presence of other alkenes, oxidation sensitive moieties and other functional groups; the mild conditions (r.t.) used in all three steps make this a viable general alternative to ozonolysis and especially for use under flow or continuous batch conditions.
- Mecozzi, Francesco,Dong, Jia Jia,Angelone, Davide,Browne, Wesley R.,Eisink, Niek N. H. M.
-
supporting information
p. 7151 - 7158
(2019/11/16)
-
- Method for synthesizing aromatic aldehyde through iron catalyzed oxidation allyl aromatic compound
-
The invention discloses a method for synthesizing aromatic aldehyde through an iron catalyzed oxidation allyl aromatic compound. According to the specific method, under the promotion effect of hydrogen silane, with air or oxygen as the oxidant, the aromatic aldehyde compound is synthesized through the iron catalyzed oxidation allyl aromatic compound, the reaction temperature is 20-150 DEG C, and the time is 0.25-60 h. The method has the advantages that a catalyst source is wide, the price is low and the environment is protected; an oxidant source is wide, the price is low and no waste is generated; the reaction conditions are mild, selectivity is high and the yield is high; a substrate source is wide and stable; a substrate functional group is high in compatibility and a substrate is widein application range; complicated small molecules are compatible and can be well converted into aldehyde. The target product separation yield can reach up to 96% under the optimized reaction conditions.
- -
-
Paragraph 0117-0119; 0151
(2019/06/27)
-
- Generation of Phosphoranyl Radicals via Photoredox Catalysis Enables Voltage-Independent Activation of Strong C-O Bonds
-
Despite the prevalence of alcohols and carboxylic acids as functional groups in organic molecules and the potential to serve as radical precursors, C-O bonds remain difficult to activate. We report a synthetic strategy for direct access to both alkyl and acyl radicals from these ubiquitous functional groups via photoredox catalysis. This method exploits the unique reactivity of phosphoranyl radicals, generated from a polar/SET crossover between a phosphine radical cation and an oxygen-centered nucleophile. We show the desired reactivity in the reduction of benzylic alcohols to the corresponding benzyl radicals with terminal H atom trapping to afford the deoxygenated products. Using the same method, we demonstrate access to synthetically versatile acyl radicals, which enables the reduction of aromatic and aliphatic carboxylic acids to the corresponding aldehydes with exceptional chemoselectivity. This protocol also transforms carboxylic acids to heterocycles and cyclic ketones via intramolecular acyl radical cyclizations to forge C-O, C-N, and C-C bonds in a single step.
- Stache, Erin E.,Ertel, Alyssa B.,Rovis, Tomislav,Doyle, Abigail G.
-
p. 11134 - 11139
(2018/11/21)
-
- The preparation method of the m (by machine translation)
-
The invention belongs to the chemical field, in particular to the field of medical synthesis, more in particular to a m-formaldehyde preparation method. The present m industrial synthesis in the low yield, high cost, and cause pollution and the like, providing a new m-formaldehyde preparation method, in order to xylene as raw materials, prepared by catalytic oxidation m, thus can effectively control the oxidation degree, high selective synthesis of toluene-phthalaldehyde, reduce the product film forming, the content of the carboxylic acid by-product, at the same time can effectively reduce the waste water waste discharge. To realize high-yield, high-purity, can be industrially large-scale green synthetic m formaldehyde. (by machine translation)
- -
-
Paragraph 0020; 0035; 0036
(2017/06/20)
-
- Method for synthesizing isophthalaldehyde
-
The invention discloses a method for synthesizing isophthalaldehyde. The method includes the following steps that firstly, m-xylene is used for chlorination to synthesize benzyl chloride; secondly, the obtained benzyl chloride is oxidized and hydrolyzed to obtain isophthalaldehyde, wherein an oxidant used in the method is urotropine. The method for synthesizing isophthalaldehyde is easy to operate and low in protection requirement, and raw materials in use are low in price so that the method can be conveniently used and popularized.
- -
-
Paragraph 0036-0053
(2017/08/28)
-
- Efficient and Highly Selective Solvent-Free Oxidation of Primary Alcohols to Aldehydes Using Bucky Nanodiamond
-
Selective oxidation of alcohols to aldehydes is widely applicable to the synthesis of various green chemicals. The poor chemoselectivity for complicated primary aldehydes over state-of-the-art metal-free or metal-based catalysts represents a major obstacle for industrial application. Bucky nanodiamond is a potential green catalyst that exhibits excellent chemoselectivity and cycling stability for the selective oxidation of primary alcohols in diverse structures (22 examples, including aromatic, substituted aromatic, unsaturated, heterocyclic, and linear chain alcohols) to their corresponding aldehydes. The results are comparable to reported transition-metal catalysts including conventional Pt/C and Ru/C catalysts for certain substrates under solvent-free conditions. The possible activation process of the oxidant and substrates by the surface oxygen groups and defect species are revealed with model catalysts, ex situ electrochemical measurements, and ex situ attenuated total reflectance. The zigzag edges of sp2 carbon planes are shown to play a key role in these reactions.
- Lin, Yangming,Wu, Kuang-Hsu Tim,Yu, Linhui,Heumann, Saskia,Su, Dang Sheng
-
p. 3497 - 3505
(2017/09/15)
-
- Palladium-Catalyzed Formylation of Aryl Iodides with HCOOH as CO Source
-
A facile and practical method for the synthesis of aromatic aldehydes by palladium-catalyzed reductive carbonylation starting from aryl iodides and HCOOH is described. Compared to the known formylation procedure, HCOOH serves not only as the most convenient and environmental-friendly C1 source but also as the reviving agent in the reductive elimination process of a Pd-catalyst. Furthermore, this procedure is also applied successfully to the modification of natural products, such as vindoline, tabersonin, and vincamine, to obtain the corresponding products in good yields.
- Sun, Guanglong,Lv, Xue,Zhang, Yinan,Lei, Min,Hu, Lihong
-
supporting information
p. 4235 - 4238
(2017/08/23)
-
- Ligandless Palladium-Catalyzed Reductive Carbonylation of Aryl Iodides under Ambient Conditions
-
Ligandless palladium-catalyzed reductive carbonylation of aryl iodides for the synthesis of aromatic aldehydes has been developed. This carbonylation process proceeded effectively even under ambient temperature and pressure. In addition, this method enables successive reductive carbonylation of diiodobenzenes to furnish dialdehydes in satisfactory yields. Finally, the nature of the active catalytic species is discussed.
- Han, Wei,Liu, Binbin,Chen, Junjie,Zhou, Qing
-
supporting information
p. 835 - 840
(2017/04/06)
-
- Method for preparing m-phthalaldehyde by mother liquor recycling
-
The invention discloses a method for preparing m-phthalaldehyde by mother liquor recycling. The method comprises the following steps: under stirring, dissolving urotropine and m-xylylenediamine in water and dropwise adding hydrochloric acid to regulate the pH; b, performing heating reflux reaction on reaction liquid of which the pH is regulated, controlling the pH of the reaction liquid through the hydrochloric acid in the reaction process, cooling and filtering after the completion of reaction, wherein the obtained solid is the m-phthalaldehyde, and the obtained mother liquor is recycled; c, concentrating the mother liquor obtained in the step b to below 70 percent of the original volume and cooling for standby; d, adding urotropine and m-xylylenediamine or an aqueous solution of the urotropine and the m-xylylenediamine into the mother liquor obtained in the step c, dropwise adding hydrochloric acid to regulate the pH and repeating the step b. The m-phthalaldehyde is prepared by the method disclosed by the invention; the recycling of the mother liquor after reaction is realized, and the utilization rate of the urotropine is improved, therefore, the production cost is reduced, and the discharge of waste liquor is reduced; the method has a great significance in the realization of m-phthalaldehyde industrialization and has better economic and social values.
- -
-
Paragraph 0014-0016
(2017/03/14)
-
- IBX oxidation of benzenedimethanols in the presence of cucurbit[8]uril
-
The cucurbit[8]uril (Q[8]) mediated oxidation of benzenedimethanols with o-iodoxybenzoic acid (IBX) in aqueous solution has been investigated, and the results reveal the supramolecular catalysis depends on the electronic and geometric structure of substrate. In the cases of o-benzenedimethanol (1a) and m-benzenedimethanol (1b), the IBX oxidation could be obviously enhanced by the addition of Q[8] at different extent. There is no observation of the catalytic activity of Q[8] when p-benzenedimethanol (1c) is subjected to the IBX oxidation. The addition amount of Q[8] is discussed herein, and the addition of more than 10% mol catalyst cannot improve the oxidation much more. The investigation of host-guest interactions by isothermal titration calorimetry implies the supramolecular catalysis is related to the formation of complexes between benzenedimethanols and cucurbit[8]uril. The supramolecular catalysis of Q[8] (cucurbit[8]uril) on the IBX (o-iodoxybenzoic acid) oxidation of o,m,p-benzenedimethanols in aqueous solvent and the host-guest interactions have been investigated.
- Cong, Hang,Chen, Qiuju,Geng, Qingxia,Tao, Zhu,Yamato, Takehiko
-
p. 545 - 549
(2015/05/27)
-
- Synthesis and thermal stability of new polynitrostilbenes
-
New polynitrostilbenes were directly synthesised by the Knoevenagel condensation of aromatic aldehydes with nitrotoluenes. The differential scanning calorimetry results demonstrated that the introduction of an amino group and C≤C double bonds could improve the thermal stability.
- Wei, Jianping,Li, Fangmei,Xu, Junhui,Peng, Xinhua
-
p. 919 - 925
(2015/06/25)
-
- Development of a Rhodium(II)-Catalyzed Chemoselective C(sp3)-H Oxygenation
-
We report the first example of RhII-catalyzed chemoselective double C(sp3)-H oxygenation, which can directly transform various toluene derivatives into highly valuable aromatic aldehydes with great chemoselectivity and practicality. The critical combination of catalyst Rh(OAc)2, oxidant Selectfluor, and solvents of TFA/TFAA promises the successful delivery of the oxidation with satisfactory yields. A possible mechanism involving a unique carbene-Rh complex is proposed, and has been supported by both experiments and theoretical calculations.
- Lin, Yun,Zhu, Lei,Lan, Yu,Rao, Yu
-
supporting information
p. 14937 - 14942
(2015/10/19)
-
- Versatile syntheses of optically pure pce pincer ligands: Facile modifications of the pendant arms and ligand backbones
-
A series of chiral C-stereogenic PCP and PCN ligand precursors were prepared in situ from inexpensive achiral starting materials via a simple catalytic asymmetric P-H addition reaction in good overall yields. This facile catalytic method of preparing the ligand backbones renders easy and economical modifications of the electronically crucial para-substituent, chiral functionalities, and donor atoms for different transition metal ions. A one-pot synthetic procedure was used efficiently to prepare the corresponding optically pure pincer complexes. All the new complexes were characterized by NMR and mass spectroscopy. The molecular structures of several selected complexes have also been elucidated by X-ray crystallography. Preliminary studies indicated that minor structural changes on these novel pincer complexes affect their chemical properties significantly when they were applied as catalysts for the reaction between diphenylphosphine and chalcone.
- Yang, Xiang-Yuan,Tay, Wee Shan,Li, Yongxin,Pullarkat, Sumod A.,Leung, Pak-Hing
-
supporting information
p. 1582 - 1588
(2015/05/13)
-
- Fukuyama reduction and integrated thioesterification/fukuyama reduction of thioesters and acyl chlorides using continuous flow
-
Fukuyama reduction of thioesters has been achieved using a polymer-supported Pd[0] catalyst (Pd/XAD-4), and continuous flow conditions. The generality of this reaction is good with a range of aldehydes prepared in excellent yields. In addition, an integrated multistep thioesterfication/ Fukuyama reduction has been developed that allows acyl chlorides to be directly converted to the corresponding aldehydes. Integral to this process is the use of polymer-supported amine and isocyanate reagents to achieve thioesterification and scavenge unreacted thiol. In addition, catch-and-release purification has been employed to enable isolation of the aldehyde from silylthioether byproducts without the need for chromatographic purification.
- Asadi, Mousa,Bonke, Shannon,Polyzos, Anastasios,Lupton, David W.
-
p. 2070 - 2074
(2014/06/24)
-
- Poly(4-vinylpyridinium) perchlorate as an efficient solid acid catalyst for the chemoselective preparation of 1,1-diacetates from aldehydes under solvent-free conditions
-
Poly(4-vinylpyridinium) perchlorate has been used as a supported, recyclable, environmentally-benign catalyst for the formation of acylals from aliphatic and aromatic aldehydes in good to excellent yields under solvent-free conditions. Notably, the reaction conditions were tolerant of ketones. This methodology offers several distinct advantages, including its operational simplicity and high product yield, as well as being green in terms of avoiding the use of toxic catalysts and solvents. Furthermore, the catalyst can be recovered and reused several times without any loss in its activity.
- Khaligh, Nader Ghaffari
-
p. 329 - 334
(2014/04/03)
-
- Sulfonated rice husk ash (RHA-SO3H): A highly powerful and efficient solid acid catalyst for the chemoselective preparation and deprotection of 1,1-diacetates
-
Rice husk ash (RHA), as a source of amorphous silica, was treated with chlorosulfonic acid and sulfonated rice husk ash (RHA-SO3H) as a highly powerful solid acid catalyst was obtained and characterized with a variety of techniques including IR, TGA, SEM, XRD, pH analysis, Hammett acidity function and BET method. This solid acid showed excellent catalytic activity for the protection and deprotection of aldehydes with Ac2O at room temperature under solvent free conditions. The procedure gave the products in excellent yields in very short reaction times and good to high yields. Also this catalyst can be reused for several times without loss of its catalytic activity.
- Shirini, Farhad,Mamaghani, Manouchehr,Seddighi, Mohadeseh
-
-
- Ultrasound assisted the chemoselective 1,1-diacetate protection and deprotection of aldehydes catalyzed by poly(4-vinylpyridinium)hydrogen sulfate salt as a eco-benign, efficient and reusable solid acid catalyst
-
Poly(4-vinylpyridinium) hydrogen sulfate solid acid was found to be efficient catalyst for preparation of 1,1-diacetate using ultrasound irradiation at ambient temperature and neat condition. Deprotection of the resulting 1,1-diacetates were achieved using the same catalyst in methanol solvent under ultrasound irradiation at room temperature. This new method consistently has the advantage of excellent yields and short reaction times. Utilization of solvent free, simple reaction conditions, isolation, and purification makes this manipulation very interesting from an economic and environmental perspective. Further, the catalyst can be reused and recovered for several times.
- Khaligh, Nader Ghaffari,Shirini, Farhad
-
supporting information
p. 19 - 25
(2013/01/15)
-
- Room temperature aerobic oxidation of alcohols using CuBr2 with TEMPO and a tetradentate polymer based pyridyl-imine ligand
-
A series of tetradentate pyridyl-imine terminated Schiff-base ligands has been investigated for their ability in the catalytic oxidation of alcohols when combined with copper bromide (CuBr2) and 2,2,6,6- tetramethylpiperidyl-1-oxy (TEMPO). Analogous bidentate ligands showed poorer catalytic activity and the ratio of Cu:ligand was of crucial importance in maintaining high yields. The polydimethylsiloxane (PDMS) derived pyridyl-imine terminated ligand combined with copper(II) ions affords an effective and selective catalyst for aerobic oxidations of primary and secondary alcohols under aqueous conditions. Preliminary mechanistic studies suggest that bimetallic complexes may be playing a role in the catalytic transformation.
- Hu, Zhenzhong,Kerton, Francesca M.
-
experimental part
p. 332 - 339
(2012/03/26)
-
- Rice husk supported FeCl3 nanoparticles as an efficient and reusable catalyst for the chemoselective 1,1-diacetate protection and deprotection of aldehydes
-
1,1-Diacetates were produced from a variety of aromatic aldehydes using rice husk supported FeCl3 nanoparticles as a catalyst. The procedure generally resulted in good yields (98%) of aromatic aldehydes including those carrying electron donating- or withdrawing-substituents. Deprotection of the resulting 1,1-diacetates was also achieved using the same catalyst in ethanol. This new method consistently has the advantages of excellent yields and relatively short reaction times. Further, the catalyst can be reused and recovered for several times.
- Shirini, Farhad,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali
-
-
- Introduction of N-sulfonic acid poly(4-vinylpyridinum) chloride as an efficient and reusable catalyst for the chemoselective 1,1-diacetate protection and deprotection of aldehydes
-
N-sulfonic acid poly(4-vinylpyridinium) chloride is easily prepared by the reaction of poly(4-vinylpyridine) with neat chlorosulfonic acid. This reagent can be used as an efficient catalyst for the preparation of 1,1-diacetates at room temperature and neat condition. Deprotection of the resulting 1,1-diacetates can also be achieved using the same catalyst in methanol. This new method consistently has the advantages of excellent yields and short reaction times. Further, the catalyst can be reused and recovered for several times.
- Shirini, Farhad,Jolodar, Omid Goli
-
experimental part
p. 61 - 69
(2012/04/17)
-
- Low-pressure hydrogenation of arenecarboxylic acids to aryl aldehydes
-
A highly effective palladium catalyst has been developed that allows the selective hydrogenation of arenecarboxylic acids to the aryl aldehydes in the presence of pivalic anhydride already at 5 bar hydrogen pressure. With the new catalyst, diversely functionalized aromatic and heteroaromatic aldehydes are conveniently accessible from the corresponding carboxylic acids in a single reaction step without any overreduction to the alcohols.
- Goossen, Lukas J.,Khan, Bilal Ahmad,Fett, Thomas,Treu, Matthias
-
supporting information; experimental part
p. 2166 - 2170
(2010/11/04)
-
- The stability of imine-containing dynamic [2]rotaxanes to hydrolysist
-
Large amounts (> 100 mol equivalents) of water are required to effect by hydrolysis the partial disassembly of the rings from the dumbbell components of two dynamic [2]rotaxanes. The two dynamic [2]rotaxanes are comprised of [24]crown-8 rings-each of which incorporate two imine bonds-encircling a dumbbell component composed of a dibenzylammonium ion in which each of the two benzyl substituents carries two methoxyl groups attached to their 3- and 5-positions. A mechanism for the partial disassembly of the two dynamic [2]rotaxanes, involving the cleavage of the kinetically labile imine bonds by water molecules, is proposed. The most important experimental observation to be noted is the fact that the hydrolysis of the macrocyclic diimines, associated with the templating -CH2NH2+CH 2-centres in the middle of their dumbbells, turns out to be an uphill task to perform in the face of the molecular recognition provided by strong [N+-H ... O] hydrogen bonds and weaker, yet not insignificant, [C-H ... O] interactions. The dynamic nature of the imine bond formation and hydrolysis is such that the acyclic components produced during hydrolysis of the imine bonds can be enticed to cyclise once again around the -CH 2NH2+CH2-template, affording the [2]rotaxanes. The reluctance of imine bonds, present in substantial numbers in larger molecular and extended structures, is significant when it comes to exercising dynamic chemistry in compounds where multiple imine bonds are present. The Royal Society of Chemistry 2010.
- Leung, Ken Cham-Fai,Wong, Wing-Yan,Arico, Fabio,Haussmann, Philip C.,Fraser Stoddart
-
scheme or table
p. 83 - 89
(2010/04/06)
-
- Convenient and versatile synthesis of formyl-substituted benzoxaboroles
-
Despite of the medicinal significance of benzoxaboroles, with the newly discovered clinical compound AN2690 as an example, the synthetic method for rapid diversification of this novel scaffold is lacking. To this end, a versatile and scalable synthesis of formyl-substituted benzoxaboroles is described here. A key step is the mono-oxidation of the two hydroxyls in compound 4 by taking advantage of the stable oxaborole ring in non-coordinating solvents, which was devised based on the study of the intramolecular coordination and exchange properties.
- Ye, Long,Ding, Dazhong,Feng, Yiqing,Xie, Dongsheng,Wu, Puhua,Guo, Hui,Meng, Qingqing,Zhou, Huchen
-
experimental part
p. 8738 - 8744
(2009/12/28)
-
- Palladium-catalyzed aerobic alcohol oxidation supported by a new type of α-diimine ligands
-
A series of new ionic sulfonated α-diimine ligands were prepared and employed as supporting ligands for the palladium-catalyzed aerobic alcohol oxidation. The electronic properties, rigidity, and steric hindrance of ligands have remarkable influences upon the catalytic activity of the palladium complexes. The best catalytic result could be achieved using ligand 9 with an electron-withdrawing sulfonyl substituent together with bulky groups (iso-propyl in 2,6-positions). This diimine/palladium-catalyzed system is highly efficient for the oxidation of various benzylic alcohols, and showed moderate yields for the secondary aliphatic alcohols and cyclic alcohols.
- Zhou, Jin,Li, Xiaoyan,Sun, Hongjian
-
p. 782 - 790
(2008/12/20)
-
- Forming germicidal aromatic dialdehydes with acetals
-
Methods of forming germicidal aromatic dialdehydes by hydrolyzing acetals are disclosed. Compositions and kits including both germicidal aromatic dialdehydes and acetals that are capable of being converted to germicides are disclosed. In one aspect, an acetal may be converted to germicide gradually in a deployed germicidal solution to accommodate for loss of the germicide or otherwise to modify the germicidal efficacy of the deployed germicidal solution.
- -
-
Page/Page column 13
(2008/06/13)
-
- Synthesis of trans-1,8,12,13-tetraoxadispiro[4.1.4.2]-tridecanes - A new class of peroxides
-
The synthesis of trans-1,8,12,13-tetraoxadispiro[4.1.4.2]tridecanes, a new class of peroxide skeletons using Birch reduction of aromatic compounds followed by ozonolysis and acid catalysed cyclisation is described.
- Naveen Kumar,Sudhakar,Rao, B. Venkateswara,Kishore, K. Hara,Murty, U. Suryanarayana
-
p. 771 - 774
(2007/10/03)
-
- Conversion of Benzal Halides to Benzaldehydes in the Presence of Aqueous Dimethylamine
-
Aqueous dimethylamine is an efficient reagent for the conversion of a variety of benzal halides to their corresponding benzaldehydes. Studies indicate that aqueous dimethylamine significantly accelerates aldehyde formation from benzal halide precursors, as compared to the use of water alone. Indeed, these reactions are routinely completed in one hour or less, depending upon substrate substitution. Desired products can be isolated in pure form, and in high yield, but silica gel filtration is often necessary to remove baseline contaminants. The method represents a novel, economical approach to acquire pure, substituted benzaldehydes from commercially available, or easily prepared starting materials.
- Bankston, Donald
-
p. 283 - 289
(2007/10/03)
-
- A facile and selective synthetic method for the preparation of aromatic dialdehydes from diesters via the amine-modified SMEAH reduction system
-
A new reduction system employing N-methylpiperazine-modified sodium bis(2-methoxyethoxy)aluminum hydride (NMP-SMEAH) for the conversion of aromatic diesters to dialdehydes is described. The method is plain and efficient, and can be carried out under mild and operationally simple conditions applicable for large scale productions.
- Hagiya, Kazutake,Mitsui, Sunao,Taguchi, Hiroaki
-
p. 823 - 828
(2007/10/03)
-
- A Convenient Nitroxyl Radical Catalyst for the Selective Oxidation of Primary and Secondary Alcohols to Aldehydes and Ketones by O2 and H2O2 under Mild Conditions
-
A new macrocyclic tetrafunctional nitroxyl radical, I, developed by Ciba Specialty Chemicals, is a particularly effective catalyst in combination with Mn(II) and Co(II) or Cu(II) nitrates for the selective oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones by air or O 2 under mild conditions (ambient temperature and pressure) or H 2O2. A distinctive feature of I is the possibility of easy recovery and recycles, due to its low solubility, particularly as ammonium salt, in most organic solvents, which makes it especially useful for practical applications.
- Minisci, Francesco,Recupero, Francesco,Rodino, Marianna,Sala, Massimiliano,Schneider, Armin
-
p. 794 - 798
(2013/09/05)
-
- Parallel Recognition by Kinetic Control with Imino Aldehyde Substrates that are Prone to Redistribution
-
One-shot treatment of a mixture of Danishefsky diene 4 and tetraallyltin 8 with 3-formylbenzylidene imines 1 in the presence of Sc(OTf)3 catalyst provides a single product 13 as a result of exclusive Diels-Alder and allylation reactions on the imine and aldehyde functions, respectively. The chemoselectivities of the respective elementary reactions are improved in the parallel reaction, and the redistribution of substrate 1 that is induced readily by Sc(OTf)3 is completely suppressed, thus offering a novel protocol for simplification of the multi-step chemical process.
- Orita, Akihiro,Nagano, Yoshifumi,Nakazawa, Koichi,Otera, Junzo
-
p. 548 - 555
(2007/10/03)
-
- Direct hydrogenation of carboxylic acids to corresponding aldehydes catalyzed by palladium complexes
-
A variety of carboxylic acids can be directly hydrogenated into the corresponding aldehydes in high yields by using homogeneous catalysts such as [Pd(PPh3)4] or combination of Pd(OAc)2 with tertiary phosphines in the presence of an excess amount of 2,2-dimethylpropionic anhydride (pivalic anhydride). As a typical example, octanoic acid can be convened into octanal in 99% yield in 3 h at 80 °C under 3.0 MPa of H2 in acetone in the presence of pivalic anhydride and a catalyst system composed of Pd(OAc)2 + 5P(p-tol)3. Such hydrogenation is widely applicable to various aliphatic, aromatic, and heterocyclic carboxylic acids as well as to di- and tribasic carboxylic acids. The process allows the presence of other functional groups such as ketonic carbonyl, nitrile, and ester groups and even internal C=C bonds. Heterogeneous palladium catalyst such as palladium on carbon also showed some catalytic activities.
- Nagayama,Shimizu,Yamamoto
-
p. 1803 - 1815
(2007/10/03)
-
- Method for production of aldehydes
-
An ether of the following formula (2): (wherein Rais a hydrogen atom, a hydrocarbon group or a heterocyclic group, Rbis a hydrogen atom, a hydroxyl group or a substituted oxy group, and Rcis a hydrocarbon group or a heterocyclic group; Raand Rcmay be combined to form a ring with the adjacent carbon atom and oxygen atom) is reacted with nitrogen monoxide in the presence of a catalyst composed of an imide compound of the following formula (1): (wherein each of R1and R2is, identical to or different from each other, a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a cycloalkyl group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or an acyl group; R1and R2may be combined to form a double bond, or an aromatic or nonaromatic ring; X is an oxygen atom or a hydroxyl group; and one or two N-substituted cyclic imido groups indicated in the formula (1) may further be formed on R1, R2, or on the double bond or aromatic or nonaromatic ring formed together by R1and R2) to give an aldehyde of the following formula (3): Ra—CHO??(3) (wherein Rahas the same meaning as defined above).
- -
-
-
- 100% selective oxygenation of p-xylene to p-tolualdehyde via photoinduced electron transfer
-
(matrix presented) The 100% selective oxygenation of p-xylene to p-tolualdehyde is initiated by photoinduced electron transfer from p-xylene to the singlet excited state of 10-methyl-9-phenylacridinium ion under visible light irradiation, yielding p-tolualdehyde exclusively as the final oxygenated product. The reason for the high selectivity in the photocatalytic oxygenation of p-xylene is discussed on the basis of the photoinduced electron transfer mechanism.
- Ohkubo, Kei,Fukuzumi, Shunichi
-
p. 3647 - 3650
(2007/10/03)
-
- A New Approach for Oxygenation Using Nitric Oxide under the Influence of N-Hydroxyphthalimide
-
An approach for partial oxygenation through a carbocation as an intermediate was successfully developed by using nitric oxide under the influence of N-hydroxyphthalimide. Thus, a variety of benzylic ethers were converted into the corresponding partially oxidized compounds, which are difficult to prepare by conventional methods, in high yields. For example, the reaction of phthalane with NO in the presence of a catalytic amount of NHPI at 60°C gave phthalaldehyde in 80% yield. The reaction was found to proceed through the formation of a hemiacetal, such as 1-hydroxyphthalane. In addition, 1,3-di-tert-butoxymethyl benzene afforded 1,3-benzenedicarbaldehyde in good yield. On the other hand, isochroman was converted into 1,1′-oxodiisochromane under these reaction conditions. The reaction of ethers with NO in the presence of a NHPI catalyst is thought to proceed via the formation of a carbocation as an intermediate. A possible reaction path was suggested.
- Eikawa, Masahiro,Sakaguchi, Satoshi,Ishii, Yasutaka
-
p. 4676 - 4679
(2007/10/03)
-
- Direct hydrogenation of carboxylic acids to corresponding aldehydes catalyzed by palladium complexes in the presence of pivalic anhydride
-
Carboxylic acids are catalytically hydrogenated into corresponding aldehydes by palladium complexes in the presence of pivalic (trimethylacetic) anhydride under H2. Less hindered aliphatic and aromatic acids are reduced to aldehydes in high yields The method is also applicable to hydrogenation of dibasic carboxylic acids and carboxylic acids containing heterocyclic groups.
- Nagayama, Kazuhiro,Shimizu, Isao,Yamamoto, Akio
-
p. 1143 - 1144
(2007/10/03)
-
- Oxidation by Chemical Manganese Dioxide. Part 3.1 Oxidation of Benzylic and Allylic Alcohols, Hydroxyarenes and Aminoarenes
-
The combined use of chemical manganese dioxide (CMD) and molecular sieves in hexane (or in acetone) in general or CMD alone in particular cases enables the convenient and efficient oxidation of benzylic and allylic alcohols, phenols and amines under relatively mild conditions.
- Hirano, Masao,Yakabe, Sigetaka,Chikamori, Hideki,Clark, James H.,Morimoto, Takashi
-
p. 770 - 771
(2007/10/03)
-
- Synthesis of carbonyl and dicarbonyl compounds from organometallic reagents and N-imidazolium-N-methyl amides and bis-amides
-
A new method for the synthesis of selective acylating agents is described from the reaction of carboxylic acids with 3-methyl-1-methylamino-3H-imidazol-1-ium salts in the presence of appropriate coupling reagents. The amides and bis-amides thus prepared reacted selectively with organometallics to afford ketones and diketones and with DIBALH to give aldehydes and dialdehydes in high yields.
- De Las Heras, Maria A.,Vaquero, Juan J.,Garcia Navio, Jose L.,Alvarez-Builla, Julio
-
p. 14297 - 14310
(2007/10/03)
-
- Compounds
-
New compounds having the general formula I STR1 wherein L may be H or D; Y may be CN or STR2 wherein A may be H, D, alkyl with 1-4 carbon atoms, OR wherein R is H or alkyl with 1-4 carbon atoms, or CR1 R2 R3 wherein R1, R2 and R3 are the same or different and are H or alkyl with 1-4 carbon atoms; Z is H, D, Y or alkyl with 1-4 C-atoms, halogen, nitro, amino, monoalkyl amino or dialkyl amino wherein the alkyl groups have 1-4 C atoms, or OR wherein R may be H or alkyl with 1-4 C-atoms, or CR4 R5 R6 wherein R4, R5 and R6 may be the same or different and may be H or F; X1 and X2 may be the same or different and may be OR, NR1 R2 or SR, wherein R, R1 and R2 may be the same or different and may be alkyl having 1-22 carbon atoms which may be branched or straight chained and/or may be further substituted; or X1 and X2 may together with the carbon atom to which they are bound form a cyclic acetal, thioacetal, dithiane, aminal, oxazolidine or thiazolidine; and pharmaceutically acceptable salts thereof. The compounds are useful as anti-cancer agents and as agents useful for the treatment of illnesses arising due to an abnormally elevated cell-proliferation.
- -
-
-
- Synthesis of aldehydes from acyl chlorides via 1-(acylmethylamino)-3-methylimidazolium salts
-
The reaction of acyl chlorides with 1-amino-3-methylimidazolium salts, followed by N-methylation of the resulting N-aminides, afforded 1-(acylmethylamino)-3-methylimidazolium sals which, upon treatment with DIBALH gave aldehydes in good yields. Analogously, dialdehydes were obtained from the corresponding bis-salts.
- De Las Heras, Maria A.,Vaquero, Juan J.,Garcia-Navio, Josel,Alvarez-Builla, Julio
-
p. 455 - 458
(2007/10/02)
-