2043-61-0Relevant articles and documents
Aerobic Oxidation of Alcohols to Carbonyl Compounds Catalyzed by N-Hydroxyphthalimide (NHPI) Combined with CoTPP-Zn2Al-LDH
Zhou, Weiyou,Chen, Dongwei,Cui, Aijun,Qian, Junfeng,He, Mingyang,Chen, Qun
, p. 295 - 299 (2017)
A catalytic system for the aerobic oxidation of alcohols by N-hydroxyphthalimide (NHPI) combined with cobalt porphyrin intercalated heterogeneous hybrid catalyst (CoTPP-Zn 2Al-LDH) has been developed. The results showed that this catalytic system can effectively catalyze the oxidation of alcohols to the corresponding carbonyl compounds. And the hybrid catalyst can be reused for five times with no appreciable reduction of activity. [Figure not available: see fulltext.]
Counterion effects in the preparation of aldehyde-bisulfite adducts
Kissane, Marie G.,Frank, Scott A.,Rener, Gregory A.,Ley, Christopher P.,Alt, Charles A.,Stroud, Paul A.,Vaid, Radhe K.,Boini, Sathish K.,McKee, Laura A.,Vicenzi, Jeffrey T.,Stephenson, Gregory A.
, p. 6587 - 6591 (2013)
The identification and development of an aldehyde-bisulfite adduct as an isolable starting material in the synthesis of the CETP inhibitor Evacetrapib are described. The physical properties of the sodium and potassium analogs are compared, and the extension of the scope of this study to include an investigation into the solid state properties of a range of sodium and potassium bisulfite adducts of commonly encountered aldehydes is discussed.
A new magnetic nanoparticle-supported Schiff base complex of manganese: An efficient and recyclable catalyst for selective oxidation of alcohols
Zhou, Qiangfei,Wan, Zijuan,Yuan, Xiaofeng,Luo, Jun
, p. 215 - 220 (2016)
A new magnetic nanoparticle-supported Schiff base complex of manganese was prepared via the copper-catalyzed 'click' reaction of an aminosalicylidene manganese complex bearing terminal alkynyl with azide-functionalized shell-core magnetic nanoparticles. T
Heterometallic Catalysts for the Oxidation of Alcohols - (R = CH3, CH2SiMe3)
Zhang, Naijie,Mann, Charles M.,Shapley, Patricia A.
, p. 6591 - 6592 (1988)
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Kinetics and Mechanism of Hydration of Alkylketenes
Allen, Annette D.,Tidwell, Thomas T.
, p. 2774 - 2780 (1987)
The hydration reactivities of CH2=C=O (1), t-Bu2C=C=O (5), Et2C=C=O (7), (CH2)4C=C=O (8), (CH2)5C=C=O (9), and t-BuCH=C=O (10) in H2O or H2O/CH3CN mixtures have been examined, including acid and base catalysis and solvent and structural isotope effects.These results provide the first systematic comparison of structural effects on the hydration of aliphatic ketenes, as well as the first measurements of base-induced hydration and pH-rate profiles for this process.The significant steric and electronic effects of the substituents observed lead to the interpretation that the acid-catalyzed reaction involves rate-limiting proton transfer to Cβ perpendicular to the ketene plane, while the H2O- and OH--induced reactions involve nucleophilic attack in the ketene plane.These results resolve the many conflicting previous reports and interpretations regarding ketene hydration.
HYDROFORMYLATION OF LESS REACTIVE OLEFINS WITH MODIFIED RHODIUM CATALYSTS
Leeuwen, P. W. N. M. van,Roobeek, C. F.
, p. 343 - 350 (1983)
The otherwise unreactive olefins (2-methyl-1-hexene, limonene, cyclohexene, methylene cyclohexane) are hydroformylated under mild conditions (90 deg C, 10 bar) in the presence of phosphite-modified rhodium catalysts.The high rates observed are attributed to the steric and electronic properties of these phosphite ligands and their ability to stabilize unsaturated rhodium species.Examples of these ligands are tris(o-t-butylphenyl) phosphite and tris(hexafluoroisopropyl) phosphite, which are, respectively, sterically demanding and strongly electron-withdrawing.
Continuous-flow aerobic oxidation of primary alcohols with a copper(I)/TEMPO catalyst
Greene, Jodie F.,Hoover, Jessica M.,Mannel, David S.,Root, Thatcher W.,Stahl, Shannon S.
, p. 1247 - 1251 (2013)
A scalable, continuous-flow process has been developed to implement a homogeneous CuI/TEMPO catalyst system for aerobic oxidation of primary alcohols to aldehydes. This catalyst system is compatible with a wide range of alcohols bearing diverse functional groups. A dilute oxygen source (9% O2 in N2) is used to avoid flammable oxygen/organic mixtures. Residence times in the heated reaction zone can be as low as 5 min with activated (e.g., benzylic) alcohols. The method has been demonstrated with nine different alcohols, including one up to 100 g scale. This flow-based catalytic method exhibits significant advantages for aerobic oxidation of alcohols, including substantially shorter residence times and broader substrate scope relative to a Pd-catalyzed method that we reported recently.
Copper/TEMPO-catalyzed aerobic alcohol oxidation: Mechanistic assessment of different catalyst systems
Hoover, Jessica M.,Ryland, Bradford L.,Stahl, Shannon S.
, p. 2599 - 2605 (2013)
Combinations of homogeneous Cu salts and 2,2,6,6-tetramethylpiperidine-N- oxyl (TEMPO) have emerged as practical and efficient catalysts for the aerobic oxidation of alcohols. Several closely related catalyst systems have been reported, which differ in the identity of the solvent, the presence of 2,2-bipyridine as a ligand, the identity of basic additives, and the oxidation state of the Cu source. These changes have a significant influence on the reaction rates, yields, and substrate scope. In this report, we probe the mechanistic basis for differences among four different Cu/TEMPO catalyst systems and elucidate the features that contribute to efficient oxidation of aliphatic alcohols.
UV light promoted 'Metal'/'Additive'-free oxidation of alcohols: Investigating the role of alcohols as electron donors
Walia, Preet Kamal,Sharma, Manik,Kumar, Manoj,Bhalla, Vandana
, p. 36198 - 36203 (2019)
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.
Photochemical Cyclohexane Carbonylation Cocatalyzed by d8 Transition Metal Carbonyls and Aromatic Ketones and Aldehydes
Boese, William T.,Goldman, Alan S.
, p. 350 - 351 (1992)
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Nitrogen-Doped, Metal-Free Activated Carbon Catalysts for Aerobic Oxidation of Alcohols
Watanabe, Hiroyuki,Asano, Sayaka,Fujita, Shin-Ichiro,Yoshida, Hiroshi,Arai, Masahiko
, p. 2886 - 2894 (2015)
Various nitrogen-doped carbon materials were prepared via treatments of an activated carbon (AC) with ammonia and hydrogen peroxide, and their catalytic performance was tested for aerobic oxidation of several alcohols in ethanol. The amount and nature of doped nitrogen-species were examined by X-ray photoelectron spectroscopy to discuss the genesis of active species by nitrogen doping. The nitrogen-doped AC catalysts are active for the oxidation of such alcohols as benzyl alcohol, cinnamyl alcohol, and 5-(hydroxymethyl)-2-furaldehyde, and in some cases, they are even more selective to the oxidation of the hydroxyl group compared with conventional Pt/C and Ru/C catalysts, for which coupling products with the ethanol solvent are formed at low conversion levels. Graphite-type doped nitrogen species are significant for the formation of active sites on the surface of AC. The present results demonstrate the potential of nitrogen-doped AC materials as metal-free, carbon-based catalysts useable for organic synthetic reactions. (Chemical Equation Presented).
Mechanism of copper(I)/TEMPO-catalyzed aerobic alcohol oxidation
Hoover, Jessica M.,Ryland, Bradford L.,Stahl, Shannon S.
, p. 2357 - 2367 (2013)
Homogeneous Cu/TEMPO catalyst systems (TEMPO = 2,2,6,6- tetramethylpiperidine-N-oxyl) have emerged as some of the most versatile and practical catalysts for aerobic alcohol oxidation. Recently, we disclosed a (bpy)CuI/TEMPO/NMI catalyst system
Atomically dispersed Rh on hydroxyapatite as an effective catalyst for tandem hydroaminomethylation of olefins
Gun, Gong,Li, Liusha,Li, Xiao,Lin, Tiejun,Qin, Tingting,Zhong, Liangshu
, (2021/07/07)
Tandem hydroaminomethylation is an efficient and green route for one-pot synthesis of amines directly from olefins. Herein, heterogeneous hydroxyapatite (HAP) supported single-atom Rh catalyst was prepared and used for tandem hydroaminomethylation of olefins. Characterization techniques confirmed the atomic dispersion of Rh species on HAP. Up to 99% conversion of 1-hexene with high selectivity to the desired amines (93.2%) was obtained over 0.5Rh1/HAP catalyst. Mechanism study demonstrated that the first hydroformylation step during the tandem catalytic process was rate-determining. Compared with the Rh nanoparticles on other oxide supports (Mg3Al, MgO and Al2O3), the atomically dispersed Rh sites on HAP ensured the high hydroformylation activity, thereby guaranteed the outstanding catalytic performance for the total tandem process. Furthermore, various corresponding amines can be obtained with satisfactory yields over 0.5Rh1/HAP catalyst from a wide scope of olefins or amines substrates.
An aerobic oxidation of alcohols into carbonyl synthons using bipyridyl-cinchona based palladium catalyst
Cheedarala, Ravi Kumar,Chidambaram, Ramasamy R.,Siva, Ayyanar,Song, Jung Il
, p. 32942 - 32954 (2021/12/02)
We have reported an aerobic oxidation of primary and secondary alcohols to respective aldehydes and ketones using a bipyridyl-cinchona alkaloid based palladium catalytic system (PdAc-5) using oxygen at moderate pressure. ThePdAc-5catalyst was analysed using SEM, EDAX, and XPS analysis. The above catalytic system is used in experiments for different oxidation systems which include different solvents, additives, and bases which are cheap, robust, non-toxic, and commercially available on the industrial bench. The obtained products are quite appreciable in both yield and selectivity (70-85%). In addition, numerous important studies, such as comparisons with various commercial catalysts, solvent systems, mixture of solvents, and catalyst mole%, were conducted usingPdAc-5. The synthetic strategy of oxidation of alcohol into carbonyl compounds was well established and all the products were analysed using1H NMR,13CNMR and GC-mass analyses.
