22270-13-9Relevant articles and documents
Acceptor-free dehydrogenation of secondary alcohols by heterogeneous cooperative catalysis between Ni nanoparticles and acid-base sites of alumina supports
Shimizu, Ken-Ichi,Kon, Kenichi,Shimura, Katsuya,Hakim, Siddiki S.M.A.
, p. 242 - 250 (2013)
Nickel-nanoparticle-loaded θ-Al2O3 (Ni/θ-Al2O3), prepared by H2-reduction of NiO/θ-Al2O3, acts as an effective and reusable heterogeneous catalyst for acceptor-free dehydrogenation of alcohols in a liquid phase. Among various supports, amphoteric supports (such as θ-Al 2O3), having both acidic and basic sites, gave higher activity than acidic or basic supports. Among Ni/θ-Al2O 3 catalysts with different Ni particle sizes, turnover frequency (TOF) per surface Ni increases with decreasing Ni particle size. These results suggest that low-coordinated Ni0 sites and metal/support interfaces play important roles in the catalytic cycle. The reaction mechanism is investigated by in situ IR study combined with kinetic analysis (kinetic isotope effect), and the following mechanism is proposed: (1) reaction of an alcohol with Lewis acid (Alδ+)-base (AlOδ-) pair site of alumina yields an alkoxide on the Alδ+ site and a proton on the AlOδ- site, (2) CH dissociation of the alkoxide by Ni 0 site to form NiH and a ketone, and (3) protolysis of NiH by a neighboring proton to release H2 gas. The proposed mechanism provides fundamental reasons for the higher activity of Ni on the acid-base bifunctional support (Al2O3) than on basic and acidic ones.
Synthesis and thermal decomposition of hydrotrioxide obtained by ozonization of exo-bicyclo[2.2.1]heptan-2-ol
Abdrakhmanova,Khalitova,Spirikhin,Dokichev,Grabovskiy,Kabal'nova
, p. 271 - 275 (2007)
Low-temperature (-70 °C) ozonization of exo-bicyclo[2.2.1]heptan-2-ol in CCl3F led to a hydrotrioxide, which was identified by 1H NMR spectroscopy. Kinetics of decomposition of given hydrotrioxide was studied by analysis of the chemiluminescence fading in the IR range of the spectrum and the activation parameters of the process were calculated. Singlet oxygen (1Δg) served as an emitter of eradiation. Yields of 1O2 in a range of temperature from -31.0 to +12.5 °C were determined (at -31 °C the yield was 37.6%). Bicyclo[2.2.1]heptan-2-one was found to be the main product of decomposition of the hydrotrioxide (the yield was 98%).
Base-induced rearrangements of bicyclo[2.2.1] and bicyclo[2.2.2]alkene-derived epoxides to ketones and alcohols
Hodgson, David M.,Marriott, Robert E.
, p. 887 - 888 (1997)
Previously unreported base-induced transformations of rigid bicycloalkene-derived epoxides (4, 8, and 16) are described, providing insight into the rearrangement mechanisms which operate following α-lithiation in such systems.
Bromine-catalyzed aerobic oxidation of alcohols
Uyanik, Muhammet,Fukatsu, Ryota,Ishihara, Kazuaki
, p. 456 - 460 (2010)
We have demonstrated that a simple and environmentally benign catalytic system HBr/NaNO2 is very effective for the selective oxidation of alcohols under balloon pressure of O2. Furthermore, the aerobic oxidation of alcohols has been achieved under balloon pressure of air rather that pure O2, with this HBr/NaNO2/HNO3 catalytic system. (Chemical equation presented).
Microbial Stereodifferentiating Reduction of Carbonyl Compounds; Proposed Quadrant Rule
Nakazaki, Masao,Chikamatsu, Hiroaki,Naemura, Koichiro,Asao, Masaaki
, p. 4432 - 4440 (1980)
The stereochemistry of the isomeric alcohols obtained from microbial reduction (Curvularia lunata and Rhodotorula rubra) of the racemic modification of bicyclic (5,8,23), benzobicyclic (11,14,17), and tricyclic(20) ketones with a wide variation in molecular framework has led to the formulation of a quadrant rule which provides information on the absolute configuration of the substrate ketone.
Catalytic alcohol oxidation using cationic Schiff base manganeseIII complexes with flexible diamino bridge
Kakavand, Meysam,Mastrorilli, Piero,Mesto, Ernesto,Neshat, Abdollah,Osanlou, Farzane,Schingaro, Emanuela,Todisco, Stefano
, (2020/11/04)
Four Schiff base manganese(III) complexes with derivatives of [(R,R)-N,N’-bis(salicy1idene)-1,2-cyclohexanediaminato)] including substituents on salicylaldehyde such as 3-methoxy, 3,5-di-tert-butyl and 3,5-chloro were synthesized and characterized using a combination of IR, UV–Vis, and HR ESI-MS techniques. The catalytic activity of these complexes was tested in the oxidation of 1-phenylethanol to acetophenone, revealing very good performances for all of the four manganese complexes. The catalytic reactions were carried out in the presence of tert-butyl hydroperoxide (TBHP) as oxidant and imidazole as co-catalyst. Complex Mn-4, bearing electron withdrawing [(R,R)-N,N’-bis(3,5-di-chloro-salicylidene)-1,2-cyclohexanediaminato)] ligand was found to be the most stable of the tested Mn(III) complexes and was selected for the oxidation of several primary and secondary alcohols.
A Structural View on the Stereospecificity of Plant Borneol-Type Dehydrogenases
Chánique, Andrea M.,Dimos, Nicole,Drienovská, Ivana,Calderini, Elia,Pantín, Mónica P.,Helmer, Carl P. O.,Hofer, Michael,Sieber, Volker,Parra, Loreto P.,Loll, Bernhard,Kourist, Robert
, p. 2262 - 2277 (2021/03/16)
The development of sustainable processes for the valorization of byproducts and other waste streams remains an ongoing challenge in the field of catalysis. Racemic borneol, isoborneol and camphor are currently produced from α-pinene, a side product from the production of cellulose. The pure enantiomers of these monoterpenoids have numerous applications in cosmetics and act as reagents for asymmetric synthesis, making an enzymatic route for their separation into optically pure enantiomers a desirable goal. Known short-chain borneol-type dehydrogenases (BDHs) from plants and bacteria lack the required specificity, stability or activity for industrial utilization. Prompted by reports on the presence of pure (?)-borneol and (?)-camphor in essential oils from rosemary, we set out to investigate dehydrogenases from the genus Salvia and discovered a dehydrogenase with high specificity (E>120) and high specific activity (>0.02 U mg?1) for borneol and isoborneol. Compared to other specific dehydrogenases, the one reported here shows remarkably higher stability, which was exploited to obtain the first three-dimensional structure of an enantiospecific borneol-type short-chain dehydrogenase. This, together with docking studies, led to the identification of a hydrophobic pocket in the enzyme that plays a crucial role in the stereo discrimination of bornane-type monoterpenoids. The kinetic resolution of borneol and isoborneol can be easily integrated into the existing synthetic route from α-pinene to camphor thereby allowing the facile synthesis of optically pure monoterpenols from an abundant renewable source.
Alcohol Oxidations by Schiff Base Manganese(III) Complexes
Neshat, Abdollah,Kakavand, Meysam,Osanlou, Farzane,Mastrorilli, Piero,Schingaro, Emanuela,Mesto, Ernesto,Todisco, Stefano
, p. 480 - 490 (2020/02/05)
Asymmetric Schiff base manganese(III) complexes involving salen ligands, N,N'-bis(salicylidene)2,3-diaminopyridine, N,N'-bis(3-methoxysalicylidene)2,3-diaminopyridine, N,N'-bis(3,5-di-tert-butylsalicylidene)2,3-diaminopyridine and N,N'-bis(3,5-di-chloro-salicylidene)2,3-diaminopyridine were prepared and their catalytic activity was investigated in the oxidation of some primary and secondary alcohols. During optimization of oxidation reactions, Mn-4, bearing electron withdrawing N,N'-Bis(3,5-di-chloro-salicylidene)2,3-diaminopyridine ligand, showed higher activity than other catalysts tested. The catalytic reactions were carried out in the presence of various oxidants such as oxygen, hydrogen peroxide or tert-butyl hydroperoxide (TBHP) and additives such as acetic acid and imidazole. The oxidant/additive combination of TBHP and imidazole was shown to be effective for the oxidation process and the degree of their impact on oxidation reaction was found highly dependent on a balanced ratio between them. Mn-4 was selected as the most effective catalyst under optimized reaction conditions and revealed efficient for the oxidation of secondary alcohols.
Oxidation of Alkenes by Water with H2 Liberation
Ben-David, Yehoshoa,Milstein, David,Tang, Shan
supporting information, p. 5980 - 5984 (2020/04/27)
Oxidation by water with H2 liberation is highly desirable, as it can serve as an environmentally friendly way for the oxidation of organic compounds. Herein, we report the oxidation of alkenes with water as the oxidant by using a catalyst combination of a dearomatized acridine-based PNP-Ru complex and indium(III) triflate. Compared to traditional Wacker-type oxidation, this transformation avoids the use of added chemical oxidants and liberates hydrogen gas as the only byproduct.
Chemoselective Continuous Ru-Catalyzed Hydrogen-Transfer Oppenauer-Type Oxidation of Secondary Alcohols
Labes, Ricardo,Battilocchio, Claudio,Mateos, Carlos,Cumming, Graham R.,De Frutos, Oscar,Rincón, Juan A.,Binder, Kellie,Ley, Steven V.
supporting information, p. 1419 - 1422 (2017/09/23)
A continuous flow method for the selective oxidation of secondary alcohols is reported. The method is based on an Oppenauer-type ruthenium-catalyzed hydrogen-transfer process that uses acetone as both solvent and oxidant. The process utilizes a low loading (1 mol%) of the commercially available ruthenium catalyst [Ru(p-cymene)Cl2]2 and triethylamine as a base and can be successfully applied to a range of different substrates, with a good level of functional group tolerance.
