- Effective chromium-mediated oxidation of allylic and benzylic alcohols by sodium percarbonate
-
High selectivity to the corresponding ketones and aldehydes has been observed for the title reaction when performed in 1,2-dichloroethane at 80°C in the presence of catalytic amounts of pyridinium dichromate and Adogen 464. The oxidation of unactivated alcohol was less efficient under these conditions.
- Muzart, Jacques,Ajjou, Abdelaziz N'Ait,Ait-Mohand, Samia
-
-
Read Online
- Supported ionic liquid phase catalysis for aerobic oxidation of primary alcohols
-
The copper-TEMPO-catalysed aerobic oxidation of primary alcohols based on the new supported ionic liquid phase (SILP) catalysts is presented. CuCl 2 acts as a homogenous catalyst dissolved in the small quantity of ionic liquid dispersed in the form of film on the solid support. A bi-modal pore structure silica with a highly developed surface and an ionogel were used as solid supports. 1-Butyl-3-methylimidazolium octylsulfate as the most active catalyst-philic phase was found. The application of SILP catalysts for the oxidation of alcohols allows the high yields of corresponding aldehydes (92-95%). The catalysts were used in seven cycles without significant loss of activity. High recoveries of the catalysts were observed.
- Chrobok, Anna,Baj, Stefan,Pud?o, Wojciech,Jarz?bski, Andrzej
-
-
Read Online
- Waste-free electrochemical oxidation of alcohols in water
-
We describe a new sol-gel molecular electrode made of a thin layer of organosilica doped with the nitroxyl radical TEMPO (2,2,6,6- tetramethylpiperidine-1-oxyl) electrodeposited on the surface of an ITO-coated glass and its employment as a selective and versatile oxidation catalyst in the electrochemical conversion of different alcohols to carbonyl compounds. Environmentally friendly water or a water/acetonitrile mixture buffered with bicarbonate is used as solvent. The electrode is highly stable and it can be reused for a prolonged period of time allowing easy separation from the products.
- Palmisano, Giovanni,Ciriminna, Rosaria,Pagliaro, Mario
-
-
Read Online
- Homogeneous CuCl2/TMEDA/TEMPO-Catalyzed chemoselective base- and halogen- free aerobic oxidation of primary alcohols in mild conditions
-
This article describes the developing of a base- and halogen- free homogeneous system aiming to chemoselectively oxidize allyl, furyl, aryl and heteroaryl primary alcohols. The current easy-to-handle aerobic system uses few amounts of CuCl2/TMEDA/TEMPO system under mild reaction conditions to produce aldehydes in high yields. Moreover, the CuCl2/TMEDA cyclic voltammetry was measured for the first time, disclosing that TMEDA as ligand substantially affects the redox potential (E1/2) of the couple E1/2Cu2+/Cu+ to E1/2Cu2+/Cu+-TMEDA by 454 mV in the redox system.
- Alves, Otávio A. L.,Chagas, Rafael C. R.,Princival, Jefferson L.,Ribeiro, RogérioT.,Silva, Emmanuel D.,Villar, José A. F. P.
-
-
- Zwitterion-induced organic-metal hybrid catalysis in aerobic oxidation
-
In many metal catalyses, the traditional strategy of removing chloride ions is to add silver salts via anion exchange to obtain highly active catalysts. Herein, we reported an alternative strategy of removing chloride anions from ruthenium trichloride using an organic [P+-N-] zwitterionic compound via multiple hydrogen bond interactions. The resultant organic-metal hybrid catalytic system has successfully been applied to the aerobic oxidation of alcohols, tetrahydroquinolines, and indolines under mild conditions. The performance of zwitterion is far superior to that of many other common Lewis bases or Br?nsted bases. Mechanistic studies revealed that the zwitterion triggers the dissociation of chloride from ruthenium trichloride via nonclassical hydrogen bond interaction. Preliminary studies show that the zwitterion is applicable to catalytic transfer semi-hydrogenation.
- Hu, Rong-Bin,Lam, Ying-Pong,Ng, Wing-Hin,Wong, Chun-Yuen,Yeung, Ying-Yeung
-
p. 3498 - 3506
(2021/04/07)
-
- Method for preparing citral through dehydrolinalool rearrangement reaction
-
The invention discloses a method for synthesizing citral by rearranging dehydrolinalool serving as a raw material. The method comprises the following steps: adding a catalytic system MoO2(acac)2 and Ph3PO into dehydrolinalool serving as the raw material in the presence of a solvent methylbenzene and an organic acid 4-tert-butylbenzoic acid, and catalyzing Meyer-Schuster rearrangement reaction to obtain citral. The catalyst system used in the invention can obtain citral with relatively high activity and selectivity and relatively ideal conversion rate and yield, the reaction process is green and environment-friendly, and harmful and odorous mercaptan and thioether are not generated. The catalytic system provides an improved method for the preparation of citral, avoids the use of sulfoxide compounds, and has a good application prospect.
- -
-
Paragraph 0023; 0024; 0025; 0026; 0027
(2021/08/14)
-
- Transition Metal-Substituted Potassium Silicotungstate Salts as Catalysts for Oxidation of Terpene Alcohols with Hydrogen Peroxide
-
Abstract: In this work, the catalytic activity of the transition metal-substituted potassium silicotungstate salts (i.e. K8-nSiMn+W11O39 (Mn+ = Cu2+, Co2+, Ni2+, Zn2+ and Fe3+) was investigated on the oxidation reactions of the terpene alcohols with H2O2 aqueous solution. The metal-substituted silicotungstate salts were easily synthesized in one-pot reactions of the precursor metal solutions (i.e. Na2WO4, Na2SiO3 and MCln) with KCl added in stoichiometric amount; after this precipitation step, the solid heteropoly salts were filtered and dried in an oven. This procedure of synthesis avoids multi-step processes that starts from the pristine heteropolyacid. The substituted metal heteropoly salts were characterized by infrared spectroscopy, measurements of the specific surface area (BET) and porosimetry by isotherms of adsorption/desorption of N2, X-rays diffraction, thermal analyses, dispersive X-rays spectroscopy, scanning electronic microscopy. The acidity strength was estimated by potentiometric titration with n-butylamine. All the salts were evaluated as catalysts in terpenic alcohols oxidation reactions with H2O2. The K5SiFeW11O39 was the most active and selective catalyst toward oxidation products. The impacts of the main reaction variables such as catalyst concentration, temperature, oxidant load, and nature of the terpene substrate were assessed. The highest activity of the K5SiFeW11O39 catalyst was assigned to the highest Lewis acidity. Graphic Abstract: [Figure not available: see fulltext.].
- da Silva, Marcio Jose,da Silva Andrade, Pedro Henrique,Sampaio, Vinicius Fernando Coelho
-
p. 2094 - 2106
(2020/11/13)
-
- An isocyanide ligand for the rapid quenching and efficient removal of copper residues after Cu/TEMPO-catalyzed aerobic alcohol oxidation and atom transfer radical polymerization
-
Transition metal catalysts play a prominent role in modern organic and polymer chemistry, enabling many transformations of academic and industrial significance. However, the use of organometallic catalysts often requires the removal of their residues from reaction products, which is particularly important in the pharmaceutical industry. Therefore, the development of efficient and economical methods for the removal of metal contamination is of critical importance. Herein, we demonstrate that commercially available 1,4-bis(3-isocyanopropyl)piperazine can be used as a highly efficient quenching agent (QA) and copper scavenger in Cu/TEMPO alcohol aerobic oxidation (Stahl oxidation) and atom transfer radical polymerization (ATRP). The addition ofQAimmediately terminates Cu-mediated reactions under various conditions, forming a copper complex that can be easily separated from both small molecules and macromolecules. The purification protocol for aldehydes is based on the addition of a small amount of silica gel followed byQAand filtration. The use ofQA?SiO2synthesizedin situresults in products with Cu content usually below 5 ppm. Purification of polymers involves only the addition ofQAin THF followed by filtration, leading to polymers with very low Cu content, even after ATRP with high catalyst loading. Furthermore, the addition ofQAcompletely prevents oxidative alkyne-alkyne (Glaser) coupling. Although isocyanideQAshows moderate toxicity, it can be easily converted into a non-toxic compound by acid hydrolysis.
- Bulska, Ewa,Enciso, Alan E.,Fantin, Marco,Grela, Karol,Lorandi, Francesca,Matyjaszewski, Krzysztof,Nogas, Wojciech,Piatkowski, Jakub,Ruszczynska, Anna,Szczepaniak, Grzegorz,Yerneni, Saigopalakrishna S.
-
p. 4251 - 4262
(2020/05/13)
-
- Oxidation of alcohols using an oxoammonium salt bearing the nitrate anion
-
A methodology for the oxidation of alcohols to the corresponding carbonyl compounds is reported using a sub-stoichiometric quantity of an oxoammonium salt bearing the nitrate counterion. The approach proves successful for the oxidation of a range of alcohol substrates including those bearing an oxygen atom β to the site of oxidation or an α-trifluoromethyl moiety. The mechanism of the reaction has been probed and also gives an insight into the previously reported nitric acid mediated oxidation of alcohols.
- Miller, Shelli A.,Sandoval, Arturo León,Leadbeater, Nicholas E.
-
supporting information
(2019/12/25)
-
- Preparation method of natural citral
-
The invention discloses a preparation method of natural citral, and belongs to the technical field of natural perfume synthesis. The preparation method comprises following steps: (1) adding a pcc reagent into a reactor, adding a proper solvent, and evenly stirring to obtain a mixed solution; (2) dropwise adding natural linalool, wherein the mass ratio of linalool to the pcc reagent is 1:3-6, and after addition, carrying out reactions for 2 to 4 hours; (3) stopping reactions, adding a water solution of sodium sulfite to quench the reactions, separating an organic layer from the reaction product, extracting the water layer by a solvent, merging the organic phases, adjusting the pH value of the organic phase by a water solution of sodium hydrogen carbonate, and collecting the organic layer; and (4) washing the organic layer, drying, and carrying out rectification to obtain natural citral. The adopted raw material namely natural linalool is easily available; and then linalool is oxidized by pcc to obtain natural citral, which is more pure and has a higher content. The natural citral meets the nature requirement of the North America market.
- -
-
Paragraph 0041-0056
(2020/03/09)
-
- A one-pot synthesis of benzimidazoles via aerobic oxidative condensation of benzyl alcohols with o-phenylenediamines catalyzed by [MIMPs]+Cl-/NaNO2/TEMPO
-
The ionic liquid 1-methyl-3-(3-sulfopropyl)imidazolium chloride ([MIMPs]+Cl-) in combination with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and sodium nitrite (NaNO2) as a catalytic system demonstrates high efficiency in the one-pot two-step aerobic oxidative condensation of benzyl alcohols with 1,2-phenylenediamines to give benzimidazoles. Various benzimidazoles are obtained in good to excellent yields by this strategy.
- Geng, Zhenzhen,Zhang, Hong-Yu,Yin, Guohui,Zhang, Yuecheng,Zhao, Jiquan
-
p. 557 - 565
(2020/03/30)
-
- Catalytic Selective Oxidation of Primary and Secondary Alcohols Using Nonheme [Iron(III)(Pyridine-Containing Ligand)] Complexes
-
The selective oxidation of different primary and secondary alcohols to carbonyl compounds by hydrogen peroxide was found to be catalyzed in conversion ranging from good to excellent by an iron(III) complex of a pyridine-containing macrocyclic ligand (Pc-L), without the need of any additive. The choice of the counteranion (Cl, Br, OTf) appeared to be of fundamental importance and the best results in terms of selectivity (up to 99 %) and conversion (up to 98 %) were obtained using the well-characterized [Fe(III)(Br)2(Pc-L)]Br complex, 4c. Magnetic moments in solid-state, also confirmed in solution ([D6]DMSO) by Evans NMR method, were calculated and point out to an iron metal center in the high spin state of 5/2. The crystal structure shows that the iron(III) center is coordinated by the four nitrogen atoms of the macrocycle and two bromide anions to form a distorted octahedral coordination environment. The catalytic oxidation of benzyl alcohol in acetonitrile was found occurring with better conversions and selectivities than in other solvents. The reaction proved to be quite general, tolerating aromatic and aliphatic alcohols, although very low yields were obtained for terminal aliphatic alcohols. Preliminary mechanistic studies are in agreement with a catalytic cycle promoted by a high-spin iron complex.
- Caselli, Alessandro,Gallo, Emma,Panza, Nicola,Rizzato, Silvia,Tseberlidis, Giorgio,di Biase, Armando
-
supporting information
p. 6635 - 6644
(2020/10/30)
-
- Preparation method of citral (by machine translation)
-
A corresponding Grignard reagent or Witititg reagent is obtained by Grignard reaction or substitution reaction of halogenated acetaldehyde acetal or tripolyhalogenated acetaldehyde and reagent 1 (magnesium powder, triphenylphosphine or triphenyl phosphite), then the obtained Grignard reagent or Wititittig reagent is reacted with 6 - methyl -5 - heptene -2 - ketone, and then subjected to acidification and deprotection to obtain citral. The preparation method has the advantages of cheap and easily available raw materials, simple operation steps, safety, environmental protection, easiness in realization, high reaction atomic economy and selectivity, high yield and purity, low product cost and suitability for green industrial production. (by machine translation)
- -
-
Paragraph 0078; 0085-0090; 0134-0136
(2020/09/09)
-
- Catalytic oxidation of alcohols using Fe-bTAML and NaClO: Comparing the reactivity of Fe(V)O and Fe(IV)O intermediates
-
We demonstrate the selective oxidation of secondary alcohols and activated primary alcohols to their corresponding aldehydes or ketones using Fe-bTAML as the catalyst and sodium hypochlorite (NaClO) as the oxidant. Good to excellent yields of 80%–99% for the carbonyl compounds and turnover numbers up to ～500 was obtained with this catalytic system. The reactions are clean, performed under mild conditions (air, room temperature) and yielded sodium chloride as the only by-product. The yield and turnover number were dependent on the pH of the reaction and this difference was attributed to the different reactive intermediates that was formed at pH 7 and pH 12 (FeV(O) and FeIV(O) respectively). Reactions involving the FeV(O) intermediate oxidize secondary alcohols more efficiently than its FeIV(O) analog. This trend was reversed for the oxidation of activated primary alcohols where reactions involving FeIV(O) afforded much higher TON's. This reactivity trend can be explained from the differences in bond dissociation energy (BDE) of their corresponding one electron reduced species ([FeIV-OH], ～99 kcal/mol; [FeIII-OH], ～83 kcal/mol) as well as their relative stabilities in the solvent during reaction. This catalytic system was found to be unsuitable for nonconjugated primary alcohol due to the formation of the inactive FeIV(OMe) intermediate after one catalytic cycle.
- Jana, Sandipan,Thomas, Jithin,Sen Gupta, Sayam
-
p. 476 - 482
(2018/11/23)
-
- An Engineered Alcohol Oxidase for the Oxidation of Primary Alcohols
-
Structure-guided directed evolution of choline oxidase has been carried out by using the oxidation of hexan-1-ol to hexanal as the target reaction. A six-amino-acid variant was identified with a 20-fold increased kcat compared to that of the wild-type enzyme. This variant enabled the oxidation of 10 mm hexanol to hexanal in less than 24 h with 100 % conversion. Furthermore, this variant showed a marked increase in thermostability with a corresponding increase in Tm of 20 °C. Improved solvent tolerance was demonstrated with organic solvents including ethyl acetate, heptane and cyclohexane, thereby enabling improved conversions to the aldehyde by up to 30 % above conversion for the solvent-free system. Despite the evolution of choline oxidase towards hexan-1-ol, this new variant also showed increased specific activities (by up to 100-fold) for around 50 primary aliphatic, unsaturated, branched, cyclic, benzylic and halogenated alcohols.
- Heath, Rachel S.,Birmingham, William R.,Thompson, Matthew P.,Taglieber, Andreas,Daviet, Laurent,Turner, Nicholas J.
-
p. 276 - 281
(2019/01/04)
-
- Efficient aerobic oxidation of alcohols catalyzed by NiGa hydrotalcites in the absence of any additives
-
The aerobic oxidation of alcohol catalyzed by NiGa hydrotalcites in the absence of any additives has been studied in detail. The research results revealed that the surface basicity significantly affected the catalytic performance. Moreover, the Br?nsted OH basic site on Ni-containing hydrotalcites was suggested to be the key active site and accelerated the oxidation. The catalytic system had good tolerance for various alcohols, and an excellent selectivity of aldehyde could be obtained for the oxidation of primary alcohol. A probable non-radical reaction path for the transformation has been proposed according to the catalytic results, isotope labelling experiments and Hammett experiments.
- Sun, Fuan,Zhou, Jiacheng,Zhou, Weiyou,Pan, Jiugao,Qian, Junfeng,He, Mingyang,Chen, Qun
-
p. 4029 - 4035
(2018/03/21)
-
- Selective Oxidation of Activated Alcohols by Supported Gold Nanoparticles under an Atmospheric Pressure of O2: Batch and Continuous-Flow Studies
-
In the hunt for a simple, mild, and scalable protocol for gold nanoparticle-catalyzed oxidation of benzylic and allylic alcohols under O2, we have used commercially available gold nanoparticles supported on alumina to selectively oxidize a large range of activated alcohols to the corresponding carbonyl compounds in good yields (68–99 %) and with excellent selectivity (ca. 100 %). The true heterogeneous nature of the catalysis by gold was demonstrated, allowing us to further adapt this protocol to continuous-flow reactors by using the tube-in-tube technology, in which higher yields were obtained thanks to an improved oxygenation of the reaction medium.
- Giorgi, Pascal D.,Elizarov, Nelli,Antoniotti, Sylvain
-
p. 1830 - 1836
(2017/05/29)
-
- Platinum-catalyzed α,β-unsaturated carbene formation in the formal syntheses of frondosin B and liphagal
-
Formal syntheses of tetracyclic terpenoids frondosin B and liphagal are described. Both synthetic routes rely on the use of platinum-catalyzed α,β-unsaturated carbene formation for the key C-C bond forming transformations. The successful route toward frondosin B utilizes a formal (4 + 3) cycloaddition, while the liphagal synthesis features the vinylogous addition of an enol nucleophile as a key step. Both synthetic routes are discussed, revealing insights into structural requirements in the catalytic a,β-unsaturated carbene reaction manifold.
- Huynh, Khoi Q.,Seizert, Curtis A.,Ozumerzifon, Tarik J.,Allegretti, Paul A.,Ferreira, Eric M.
-
supporting information
p. 294 - 297
(2017/11/28)
-
- Method for preparing aldehyde ketone by efficiently catalyzing molecular oxygen to oxidize alcohol by taking hydrotalcite-like material as catalyst
-
The invention belongs to the technical field of liquid-phase catalytic oxidation and provides a method for preparing aldehyde ketone by efficiently catalyzing molecular oxygen to oxidize alcohol by taking a hydrotalcite-like material as a catalyst. The catalyst can be expressed as A-NixM-LDHs (A=OH, CO3, CH3COO and PO4; M is Ga or In; the ratio of Ni to M is (2-4) to 1). The method is characterized by preparing aldoketones compounds by carrying out aerobic oxidation reaction on alcohol under mild condition without adding additives in the presence of the catalyst. The hydrotalcite-like material can be synthesized in quantity and can be recycled; the method has the advantages of high selectivity and yield of aldehyde ketone, mild reaction condition, low cost and easiness in realizing industrialization.
- -
-
Paragraph 0036; 0037; 0038; 0039; 0041
(2017/09/29)
-
- Secondary Phosphine Oxides as Multitalented Preligands En Route to the Chemoselective Palladium-Catalyzed Oxidation of Alcohols
-
Secondary phosphine oxides O=PHR2 (SPOs) were identified as multitalented preligands for the chemoselective Pd-catalyzed oxidation of alcohols by a hydrogen-abstracting methodology. SPOs were found to promote the hydrogen-abstraction step as well as hydrogen transfer to a Michael acceptor by generating a putative active H?Pd species. The catalytic system operates under neutral conditions and was proven to be compatible with various electrophilic and nucleophilic functionalities within the substrates as well as water- and air-sensitive functional groups.
- Vasseur, Alexandre,Membrat, Romain,Gatineau, David,Tenaglia, Alphonse,Nuel, Didier,Giordano, Laurent
-
p. 728 - 732
(2017/03/13)
-
- Bicatalytic Multistep Reactions En Route to the One-Pot Total Synthesis of Complex Molecules: Easy Access to Chromene and 1,2-Dihydroquinoline Derivatives from Simple Substrates
-
By combining nanocatalysis with base catalysis, a novel one-pot multistep process was found for the synthesis of substituted heterocycles of biological relevance from simple substrates. The process is based on the initial Au/O2 oxidation of allylic alcohols, which is followed by base-catalyzed tandem hetero-Michael/aldolization/crotonization with ortho-hydroxy- or ortho-aminobenzaldehydes. The flexibility of the reaction even allowed the benzaldehyde partner to be prepared in situ in an example of a one-pot/five-step process.
- Giorgi, Pascal D.,Miedziak, Peter J.,Edwards, Jennifer K.,Hutchings, Graham J.,Antoniotti, Sylvain
-
-
- Visible-Light-Induced Efficient Selective Oxidation of Nonactivated Alcohols over {001}-Faceted TiO2 with Molecular Oxygen
-
In the presence of molecular oxygen, a {001}-faceted nanocrystalline anatase TiO2 catalyst enabled the selective oxidation of nonactivated aliphatic alcohols to the corresponding aldehydes or ketones under visible light. The reaction shows excellent conversion and selectivity towards the formation of the carbonyl products without over-oxidation to the corresponding carboxylic acids. The exceptional reactivity of the catalyst is possibly due to the absorption of visible light originating from a stronger interaction of alcohol with the {001} facet, which facilitates the modification of the band structure of TiO2, thus facilitating the photogenerated hole transfer and subsequent oxidation processes. The experimental results have also been corroborated by first-principles quantum chemical DFT calculations.
- Vadakkekara, Raji,Biswas, Abul Kalam,Sahoo, Tapan,Pal, Provas,Ganguly, Bishwajit,Ghosh, Subhash Chandra,Panda, Asit Baran
-
supporting information
p. 3084 - 3089
(2016/11/13)
-
- Sonochemical synthesis of PdO@silica as a nanocatalyst for selective aerobic alcohol oxidation
-
Abstract A sonochemical method has been employed for the synthesis of palladium oxide (PdO) nanoparticles deposited on silica nanoparticle. By sonochemical process, the PdO nanoparticles were doped on the surface of silica at room temperature and atmospheric pressure with short reaction time. Silica nanoparticles were used as a supporting material to suppress aggregation and thereby to increase surface area of PdO nanoparticles. Fabricated PdO-doped silica nanoparticle (PdO@SNP) was applied as a nanocatalyst for selective alcohol oxidation reaction in the presence of molecular oxygen. The PdO@SNP composite showed higher catalytic activity and selectivity than unsupported PdO nanoparticle for aerobic alcohol oxidation reaction.
- Seok, Seunghwan,Hussain, Muhammad Asif,Park, Kyun Joo,Kim, Jung Won,Kim, Do Hyun
-
p. 178 - 184
(2015/08/06)
-
- Long-chain NHC-stabilized RuNPs as versatile catalysts for one-pot oxidation/hydrogenation reactions
-
The synthesis and catalytic activity of long-chain NHC-stabilized RuNPs are presented. Full characterization of these novel nanostructures including surface state studies show that the ligand influences the number and the location of Ru active sites which impacts the NP catalytic activity, especially in hydrogenation reactions. The high stability and versatility of these nanosystems make them successful catalysts for both oxidation and hydrogenation reactions that can even be performed successively in a one pot-fashion.
- Martínez-Prieto,Ferry,Rakers,Richter,Lecante,Philippot,Chaudret,Glorius
-
supporting information
p. 4768 - 4771
(2016/04/09)
-
- Bioinspired aerobic oxidation of alcohols with a bifunctional ligand based on bipyridine and TEMPO
-
A novel bioinspired bifunctional ligand incorporating metal-binding site and stable free radical has been synthesized. The catalytic system obtained from the bifunctional ligand with copper(i) iodide in the presence of N-methylimidazole is highly efficient for the oxidation of a broad range of primary benzylic, allylic, alkynyl, aliphatic alcohols and secondary benzylic alcohols to the corresponding aldehydes and ketones in good to excellent yields. The catalyst system exhibits broad functional-group compatibility. The reaction is carried out in acetonitrile as solvent under air balloon at room temperature. The catalyst system features excellent activity for primary aliphatic alcohol oxidation and a high chemoselective oxidation of primary alcohols over the secondary alcohols. This oxidation process is readily amenable to larger-scale application. The interaction of the different components in the reaction mixtures was studied by UV-visible spectroscopy. The data indicated that Cu(i) existed throughout the reaction. A plausible mechanism of the catalytic cycle is proposed.
- Wang, Lianyue,Bie, Zhixing,Shang, Sensen,Lv, Ying,Li, Guosong,Niu, Jingyang,Gao, Shuang
-
p. 35008 - 35013
(2016/05/19)
-
- Acceptorless dehydrogenation of alcohols on a diruthenium(II,II) platform
-
The diruthenium(II,II) complex [Ru2(L1)(OAc)3]Cl (1), spanned by a naphthyridine-diimine ligand and bridged by three acetates, has been synthesized. The catalytic efficacy of complex 1 has been evaluated for the acceptorless dehydrogenation (AD) of alcohols and for the dehydrogenative coupling reactions of alcohols with Wittig reagents. The diruthenium(II,II) complex is an excellent catalyst for AD of a diverse range of alcohols, and it is shown to be particularly effective for the conversion of primary alcohols to the corresponding aldehydes without undesired side products such as esters. Triphenylphosphonium ylides in a one-pot reaction with alcohols afforded the corresponding olefins in high yields with excellent E selectivity. The liberated dihydrogen gas was identified and measured to be 1 equiv with respect to alcohol. Deuteration studies with PhCD2OH revealed the absence of isotope scrambling in the product, indicating the involvement of a Ru-monohydride intermediate. Kinetic studies and DFT calculations suggest a low-energy bimetallic β-hydride elimination pathway where rate-limiting intramolecular proton transfer from alcohol to metal-bound hydride constitutes the dehydrogenation step. The general utility of metal-metal bonded compounds for alcohol AD and subsequent coupling reactions is demonstrated here.
- Dutta, Indranil,Sarbajna, Abir,Pandey, Pragati,Rahaman, S. M. Wahidur,Singh, Kuldeep,Bera, Jitendra K.
-
p. 1505 - 1513
(2016/06/09)
-
- Method to oxidize alcohols selectively to aldehydes and ketones with heterogeneous supported ruthenium catalyst at room temperature in air and catalyst thereof
-
The present invention relates to a method for selectively oxidizing alcohol by using a heterogeneous catalyst for producing aldehyde and ketone in an organic synthesis process used in the laboratory and chemical industries, and a catalytic system thereof. The method can be used as an intermediate product for synthesizing medicine, scent, fragrance, and precise chemical products, and can use a heterogeneous catalyst at room temperature in air by using the catalytic system and producing alcohol and ketone.COPYRIGHT KIPO 2016
- -
-
Paragraph 0021; 0022
(2016/10/07)
-
- Citral preparation method
-
The invention relates to a preparation method for citral. The method comprises the steps of: 1) in an atmospheric pressure and oxygen-free environment, and in the presence of an alcohol ether solvent and a cosolvent, using benzoic acid or phenylacetic acid to adjust the pH value in the range of 3-5, subjecting dehydrolinalool to catalytic rearrangement under the action of a Mo catalyst, keeping the dehydrolinalool, the alcohol ether solvent, and the cosolvent in a ratio of 1:2.5:0.5, with the dosage of the catalyst accounting for 5% of the weight of the dehydrolinalool, and controlling the reaction time at 5-7h and the reaction temperature at 115-120DEG C; and 2) subjecting the citral crude product obtained in step 1) to five-stage molecular distillation for separation. By making use of the good solubility of the molybdenum catalyst in the alcohol ether solvent, the method provided by the invention not only improves the citral yield, and the catalyst can be recycled due to its dissolution in the solvent. The method avoids complex processing steps in the prior art, and simplifies the process.
- -
-
Paragraph 0025-0028; 0040
(2017/02/23)
-
- Aerobic oxidation of alcohols by copper(I)/benzoxazine ligand/TEMPO under mild and base-free conditions
-
A novel benzoxazine ligand with an imidazole moiety was synthesized. This ligand in combination with Cu(OTf) and TEMPO efficiently catalyzed aerobic oxidation of active primary alcohols and also showed good to excellent activity in the oxidation of secondary alcohols under mild and base-free conditions.
- Zhang,Huang,Lü,Cao,Zhao
-
p. 1965 - 1972
(2015/10/12)
-
- Fluorous bispidine: A bifunctional reagent for copper-catalyzed oxidation and knoevenagel condensation reactions in water
-
Fluorous bispidine-type ligands have been developed to facilitate its recovery and reusability and to demonstrate its bifunctional property as a ligand and base in copper-catalyzed aerobic oxidation, the Knoevenagel condensation and tandem oxidation/Knoevenagel condensation in water under mild conditions. Application of the fluorous ligand was also extended to the surfactant-free copper-catalyzed allylic and benzylic sp3 C-H oxidation reaction in water. The fluorous ligands could be recovered using F-SPE with recovery ranging from 91-97% and could be reused five times with little loss of activity.
- Ang, Wei Jie,Chng, Yong Sheng,Lam, Yulin
-
p. 81415 - 81428
(2015/10/06)
-
- Gas-liquid segmented flow microfluidics for screening copper/tempo-catalyzed aerobic oxidation of primary alcohols
-
Aerobic oxidation using a combination of copper salts and 2,2,6,6-tetramethylpiperidine N-oxyl (TEMPO) represent useful tools for organic synthesis and several closely related catalyst systems have been reported. To gain further insights, these catalytic systems were evaluated in a gas-liquid segmented flow device. The improvement of oxygen mass transfer has a significant influence on the turnover-limiting step. Hence, an improved catalytic system using copper(II) as copper source was implemented in a microreactor for the safe and efficient oxidation of primary alcohol.
- Vanoye, Laurent,Pablos, Mertxe,De Bellefon, Claude,Favre-Réguillon, Alain
-
p. 739 - 746
(2015/03/18)
-
- Metallopeptoids as efficient biomimetic catalysts
-
Metallopeptoid catalysts incorporating phenanthroline-copper and TEMPO, and at least one non-catalytic group perform in the oxidation of various benzylic, allylic and aliphatic primary alcohols with a TON of up to 16 times higher than a mixture of the two catalytic groups or the peptoid dimer that is lacking the non-catalytic group.
- Prathap, Kaniraj Jeya,Maayan, Galia
-
supporting information
p. 11096 - 11099
(2015/07/02)
-
- High-temperature synthesis of amides from alcohols or aldehydes by using flow chemistry
-
An efficient conversion of aliphatic and aromatic alcohols or aldehydes into the corresponding primary amides was successfully achieved by using flow chemistry. Excellent yields were obtained in very short reaction times, and thus this method offers an efficient alternative to traditional methods for amide formation.
- Ambreen, Nida,Wirth, Thomas
-
p. 7590 - 7593
(2015/04/22)
-
- CuI/N4 ligand/TEMPO derivatives: A mild and highly efficient system for aerobic oxidation of primary alcohols
-
A new system consisting of a copper(I) complex generated in situ from a tetradentate nitrogen ligand and CuI in combination with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) derivatives was successfully developed. The system was suitable for efficient and selective aerobic oxidation of primary benzyl and allyl alcohols with a wide range of functional groups to the corresponding aldehydes at room temperature. The best result was obtained with N,N'-dimethyl-N,N'-bis(2-pyridylmethyl)ethane-1,2-diamine as the ligand and 4-OH-TEMPO as a cocatalyst in CH3CN. In addition, high-resolution mass spectrometry, ultraviolet-visible spectroscopy, and electrochemical experiments were used to provide evidence of intermediates.
- Zhang, Shufang,Miao, Chengxia,Xu, Daqian,Sun, Wei,Xia, Chungu
-
p. 1864 - 1873
(2015/09/28)
-
- Chemoselective hydrogen peroxide oxidation of allylic and benzylic alcohols under mild reaction conditions catalyzed by simple iron-picolinate complexes
-
Chemoselective oxidation of allylic alcohols to α,β-unsaturated carbonyl compounds proceeded efficiently using hydrogen peroxide with iron-picolinate catalysts. The in situ generated [Fe(Me-Pic)3] (Me-Pic = 6-methylpicolinate) catalyzed oxidation of the alcohol moiety of primary allylic alcohols while the [Fe(Pic)3] (Pic = picolinate) and [Fe(Me-Pic)2(Pic)] did not show sufficient catalytic activity. the Partner Organisations 2014.
- Tanaka, Shinji,Kon, Yoshihiro,Nakashima, Takuya,Sato, Kazuhiko
-
p. 37674 - 37678
(2014/11/07)
-
- Chemoselective hydrogen peroxide oxidation of allylic and benzylic alcohols under mild reaction conditions catalyzed by simple iron-picolinate complexes
-
Chemoselective oxidation of allylic alcohols to α,β-unsaturated carbonyl compounds proceeded efficiently using hydrogen peroxide with iron-picolinate catalysts. The in situ generated [Fe(Me-Pic)3] (Me-Pic = 6-methylpicolinate) catalyzed oxidation of the alcohol moiety of primary allylic alcohols while the [Fe(Pic)3] (Pic = picolinate) and [Fe(Me-Pic)2(Pic)] did not show sufficient catalytic activity. This journal is
- Tanaka, Shinji,Kon, Yoshihiro,Nakashima, Takuya,Sato, Kazuhiko
-
p. 37674 - 37678
(2014/12/11)
-
- Efficient and convenient oxidation of alcohols to aldehydes and ketones with H2O2/(NH4)6Mo7O 24·4H2O regulated by PEG1000-DIL/ methylcyclohexane temperature-dependent biphasic system
-
A simple and efficient method for the oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones with H2O 2/(NH4)6Mo7O24·4H 2O using the PEG1000-DIL/methylcyclohexane temperature-dependent biphasic system has been developed. The product can be easily isolated by a simple decantation, and the catalytic system can be recycled or reused without loss of catalytic activity.
- Hu, Yu-Lin,Lu, Ming,Ge, Xiu-Tao
-
p. 453 - 460
(2013/07/27)
-
- Hypervalent iodine/TEMPO-mediated oxidation in flow systems: A fast and efficient protocol for alcohol oxidation
-
Hypervalent iodine(III)/TEMPO-mediated oxidation of various aliphatic, aromatic and allylic alcohols to their corresponding carbonyl compounds was successfully achieved by using microreactor technology. This method can be used as an alternative for the oxidation of various alcohols achieving excellent yields and selectivities in significantly shortened reaction times.
- Ambreen, Nida,Kumar, Ravi,Wirth, Thomas
-
p. 1437 - 1442
(2013/08/23)
-
- Oxidation of benzyl alcohols by semi-stoichiometric amounts of cobalt-doped birnessite-type layered MnO2 under oxygen atmosphere
-
Semi-stoichiometric oxidation of benzylic alcohols to benzaldehydes was readily achieved in heated toluene in the presence of cobalt-doped birnessite MnO2 under oxygen atmosphere. The oxidation took place selectively for benzylic alcohols, while allylic alcohols were oxidized slowly. No oxidation occurred for usual primary and secondary alcohols. Oxygen atmosphere was important to perform effective oxidation; i.e. the oxidation progressed much slower in nitrogen atmosphere. Cobalt-doped birnessite was the best catalyst for the oxidation, in which the amount of birnessite was reduced to 0.7 equivalent of alcohol, resulting in yields of aldehydes greater than 80%. The present method provides a useful green oxidation for benzylic alcohols.
- Kamimura, Akio,Nozaki, Yuichiro,Nishiyama, Mai,Nakayama, Masaharu
-
p. 468 - 472
(2013/04/10)
-
- Sub-stoichiometric oxidation of benzylic alcohols with commercially available activated MnO2 under oxygen atmosphere: A green modification of the benzylic oxidation
-
Benzylic and allylic alcohols were readily converted into aldehydes and ketones in the presence of sub-stoichiometric amounts of activated MnO 2 under oxygen atmosphere. No over-oxidation to carboxylic acid happened. The present procedure dramatically reduces the amounts of MnO 2 necessary for the oxidation and provides a greener modification of widely used oxidation method.
- Kamimura, Akio,Komatsu, Hiroyuki,Moriyama, Takaaki,Nozaki, Yuichiro
-
p. 5968 - 5972
(2013/07/27)
-
- Pd-nanoparticles stabilized by pyridine-functionalized poly(ethylene glycol) as catalyst for the aerobic oxidation of α,β-unsaturated alcohols in water
-
The synthesis and coordination chemistry of 4-pyridinemethylene end-capped MeO-PEG (LPy) to Pd(II) was investigated. The PEG-based macroligand LPy was straightforwardly synthesized by pyridine end-functionalization of PEG monomethyl ether and employed to stabilize Pd(II) in a neutral (1a) and bis-cationic (2a) macrocomplex, characterized by a LPy to Pd molar ratio of 2 and 4, respectively. The homogeneous distribution of the Pd-NPs in 2b exerted a significant stabilizing effect on the poly(ether) chain of LPy against its oxidative thermal degradation. From a screening of the Pd(II)- and Pd-NP-based catalysts in the aerobic oxidation of unsaturated alcohols in water emerged 2b as the most stable catalyst, showing TOF-values up to 200-h and high chemoselectivity even for prolonged reaction times.
- Giachi, Guido,Oberhauser, Werner,Frediani, Marco,Passaglia, Elisa,Capozzoli, Laura,Rosi, Luca
-
p. 2518 - 2526
(2013/08/25)
-
- Linear polystyrene-stabilized Pt nanoparticles for aerobic alcohol oxidation and hydrogen-transfer reduction in aqueous media
-
Linear polystyrene-stabilized Pt nanoparticles were prepared using phenylboronic acid and NaBH4 as the reductant. The size of Pt nanoparticles was dependent on the reductant, while the immobilization degree of Pt was not. The resultant polystyrene-stabilized Pt nanoparticles showed high catalytic activity for aerobic alcohol oxidation in water and hydrogen-transfer reduction of olefin, ketone, and nitro group using 2-propanol as a hydrogen donor. The catalyst was recycled without significant loss of activity.
- Ohtaka, Atsushi,Kono, Yuki,Inui, Shigeki,Yamamoto, Syusei,Ushiyama, Tomoki,Shimomura, Osamu,Nomura, Ry?ki
-
experimental part
p. 48 - 53
(2012/08/13)
-
- Efficient Swern oxidation and Corey-Kim oxidation with ion-supported methyl sulfoxides and methyl sulfides
-
The Swern oxidation of various benzylic and allylic alcohols, primary alcohols, and secondary alcohols with two ion-supported methyl sulfoxides A-1 (C6) and B-1 (C10), and oxalyl chloride in the presence of triethylamine in dichloromethane, followed by simple diethyl ether extraction of the reaction mixture, gave the corresponding aldehydes and ketones, respectively, in good yields with high purity. Similarly, the Corey-Kim oxidation of various benzylic and allylic alcohols, primary alcohols, and secondary alcohols with two ion-supported methyl sulfides A-2 (C6) and B-2 (C10), and N-chlorosuccinimide in the presence of triethylamine in dichloromethane, followed by simple diethyl ether extraction of the reaction mixture, furnished the corresponding aldehydes and ketones, respectively, in good yields with high purity. Both reactions did not produce any unpleasant odor at all. In the Swern oxidation, ion-supported methyl sulfides were recovered in high yields and could be re-oxidized to produce ion-supported methyl sulfoxides A-1 (C6) and B-1 (C10), for reuse in the same oxidation. In the Corey-Kim oxidation, ion-supported methyl sulfides A-2 (C6) and B-2 (C10) were recovered in high yields and could be also reused for the same oxidation.
- Tsuchiya, Daisuke,Tabata, Masayuki,Moriyama, Katsuhiko,Togo, Hideo
-
experimental part
p. 6849 - 6855
(2012/08/28)
-
- Modified Marko's aerobic oxidation of alcohols under atmospheric pressure with air or molecular oxygen at room temperature
-
A modified version of Marko's aerobic oxidation procedure, using highly pure (99.995+%) CuCl with 4,7-diphenyl-1,10-phenanthroline (dpPhen), DBAD, and Cs2CO3 (98% purity) successfully oxidized primary and secondary alcohols to the corresponding aldehydes and ketones in excellent yield at room temperature with either air or molecular oxygen under atmospheric pressure.
- Nishii, Takeshi,Ouchi, Tomomi,Matsuda, Aya,Matsubara, Yuka,Haraguchi, Yuuko,Kawano, Tomomi,Kaku, Hiroto,Horikawa, Mitsuyo,Tsunoda, Tetsuto
-
p. 5880 - 5882,3
(2020/07/31)
-
- Pyridinium o-iodoxybenzoate as a safe form of a famous oxidant
-
The stable pyridinium salt of o-iodoxybenzoic acid (PIBX) that is easy to obtain can serve as a convenient substitute of IBX as an oxidant. PIBX is safer, has neutral properties behaves as an equivalent to IBX in the oxidation of alcohols to ketones or aldehydes in polar solvents (DMF, DMSO), and provides higher oxidation rate in THF due to better solubility.
- Kumanyaev, Ivan M.,Lapitskaya, Margarita A.,Vasiljeva, Ljudmila L.,Pivnitsky, Kasimir K.
-
experimental part
p. 129 - 131
(2012/09/05)
-
- Selective oxidation of unsaturated alcohols catalyzed by sodium nitrite and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone with molecular oxygen under mild conditions
-
We have developed a simple and practical process for the oxidation of alcohols to the corresponding carbonyl compounds by using a low catalytic amount of DDQ, NaNO2 as a cocatalyst, and molecular oxygen as terminal oxidant. Nitric oxide generated in situ by NaNO2 in the presence of AcOH is essential for the realization of the catalytic cycle at room temperature. The practical utility of this catalytic process has been demonstrated in the gram-scale oxidation of cinnamyl alcohol.
- Wang, Lianyue,Li, Jun,Yang, Hua,Lv, Ying,Gao, Shuang
-
experimental part
p. 790 - 794
(2012/02/16)
-
- 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)
-
- Ruthenium-catalyzed asymmetric transfer hydrogenation of allylic alcohols by an enantioselective isomerization/transfer hydrogenation mechanism
-
Reducing hazards: A asymmetric transfer hydrogen reaction was developed to reduce prochiral allylic alcohols in high yield and excellent enantioselectivity (see example). Mechanistic studies indicate a novel enantioselective isomerization/transfer hydrogenation mechanism. This new reaction is much safer than high-pressure hydrogenation using H2 gas. Copyright
- Wu, Ruoqiu,Beauchamps, Marie G.,Laquidara, Joseph M.,Sowa Jr., John R.
-
supporting information; experimental part
p. 2106 - 2110
(2012/04/11)
-
- K-birnessite MnO2: A new selective oxidant for benzylic and allylic alcohols
-
K-birnessite, which is readily prepared by the pyrolysis of KMnO 4, acts as a convenient new oxidant for benzylic and allylic alcohols.
- Kamimura, Akio,Nozaki, Yuichiro,Ishikawa, Shingo,Inoue, Ryota,Nakayama, Masaharu
-
scheme or table
p. 538 - 540
(2011/02/28)
-
- Selective iron-catalyzed oxidation of benzylic and allylic alcohols
-
A convenient and selective oxidation of alcohols with hydrogen peroxide to give aldehydes and ketones has been developed. Using in situ generated iron chloride complexes [Fe(L3)2Cln] [n=0-1, L3 =6-(N-phenylbenzimidazoyl)-2-pyridinecarboxylic acid], aldehydes and ketones were obtained in good yield and excellent selectivity after a short reaction time at room temperature. Copyright
- Join, Benoit,Moeller, Konstanze,Ziebart, Carolin,Schroeder, Kristin,Goerdes, Dirk,Thurow, Kerstin,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
-
supporting information; experimental part
p. 3023 - 3030
(2011/12/21)
-
- Twist does a twist to the reactivity: Stoichiometric and catalytic oxidations with twisted tetramethyl-IBX
-
The methyl groups in TetMe-IBX lower the activation energy corresponding to the rate-determining hypervalent twisting (theoretical calculations), and the steric relay between successive methyl groups twists the structure, which manifests in significant solubility in common organic solvents. Consequently, oxidations of alcohols and sulfides occur at room temperature in common organic solvents. In situ generation of the reactive TetMe-IBX from its precursor iodo-acid, i.e., 3,4,5,6-tetramethyl-2-iodobenzoic acid, in the presence of oxone as a co-oxidant facilitates the oxidation of diverse alcohols at room temperature.
- Moorthy, Jarugu Narasimha,Senapati, Kalyan,Parida, Keshaba Nanda,Jhulki, Samik,Sooraj, Kunnikuruvan,Nair, Nisanth N.
-
experimental part
p. 9593 - 9601
(2012/01/03)
-
- Three-component coupling approach toward the synthesis of a resorcylic acid lactone framework
-
A resorcylic acid lactone (RAL) framework was constructed based on a three-component coupling approach. The key step was the intermolecular alkylation of a protected cyanohydrin with an aromatic scaffold, and the subsequent carbonylative esterification of the aryl iodide with an alcohol. This sequence allowed the rapid assembly of three components without extra protection/deprotection steps. This synthetic strategy enables the ketone at the 2′ position to be masked as a protected cyanohydrin during the ester formation, thus avoiding an undesired isocoumarin formation. This method should be widely applicable to the synthesis of various types of RAL frameworks.
- Sugiyama, Sakae,Fuse, Shinichiro,Takahashi, Takashi
-
scheme or table
p. 6654 - 6658
(2011/09/20)
-
- Spectro-electrochemical and DFT studies of a planar Cu(II)-phenolate complex active in the aerobic oxidation of primary alcohols
-
A square-planar compound [Cu(pyrimol)Cl] (pyrimol = 4-methyl-2-N-(2- pyridylmethylene)aminophenolate) abbreviated as CuL-Cl) is described as a biomimetic model of the enzyme galactose oxidase (GOase). This copper(II) compound is capable of stoichiometric aerobic oxidation of activated primary alcohols in acetonitrile/water to the corresponding aldehydes. It can be obtained either from Hpyrimol (HL) or its reduced/hydrogenated form Hpyramol (4-methyl-2-N-(2-pyridylmethyl)aminophenol; H2L) readily converting to pyrimol (L-) on coordination to the copper(II) ion. Crystalline CuL-Cl and its bromide derivative exhibit a perfect square-planar geometry with Cu-O(phenolate) bond lengths of 1.944(2) and 1.938(2) . The cyclic voltammogram of CuL-Cl exhibits an irreversible anodic wave at +0.50 and +0.57 V versus ferrocene/ferrocenium (Fc/Fc+) in dry dichloromethane and acetonitrile, respectively, corresponding to oxidation of the phenolate ligand to the corresponding phenoxyl radical. In the strongly donating acetonitrile the oxidation path involves reversible solvent coordination at the Cu(II) centre. The presence of the dominant CuII-L? chromophore in the electrochemically and chemically oxidised species is evident from a new fairly intense electronic absorption at 400-480 nm ascribed to a several electronic transitions having a mixed π → π*(L?) intraligand and Cu-Cl → L? charge transfer character. The EPR signal of CuL-Cl disappears on oxidation due to strong intramolecular antiferromagnetic exchange coupling between the phenoxyl radical ligand (L ?) and the copper(II) centre, giving rise to a singlet ground state (S = 0). The key step in the mechanism of the primary alcohol oxidation by CuL-Cl is probably the α-hydrogen abstraction from the equatorially bound alcoholate by the phenoxyl moiety in the oxidised pyrimol ligand, Cu-L ?, through a five-membered cyclic transition state.
- Uma Maheswari, Palanisamy,Hartl, Franti?ek,Quesada, Manuel,Buda, Francesco,Lutz, Martin,Spek, Anthony L.,Gamez, Patrick,Reedijk, Jan
-
experimental part
p. 406 - 414
(2011/09/16)
-
