91-52-1Relevant articles and documents
Heterogeneous vanadium-catalyzed oxidative cleavage of olefins for sustainable synthesis of carboxylic acids
Upadhyay, Rahul,Rana, Rohit,Sood, Aakriti,Singh, Vikash,Kumar, Rahul,Srivastava, Vimal Chandra,Maurya, Sushil K.
supporting information, p. 5430 - 5433 (2021/06/09)
The development of green and sustainable processes to synthesize active pharmaceutical ingredients and key starting materials is a priority for the pharmaceutical industry. A green and sustainable protocol for the oxidative cleavage of olefins to produce pharmaceutically and biologically valuable carboxylic acids is achieved. The developed protocol involves 70% aq. TBHP as an oxidant over a heterogeneous vanadium catalyst system. Notably, the synthesis of industrially important azelaic acid from various renewable vegetable oils is accomplished. The catalyst could be recycled for up to 5 cycles without significant loss in yield and the protocol was successfully demonstrated at the gram-scale.
Continuous production method of benzoic acid derivative
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Paragraph 0032-0034, (2021/11/14)
The invention relates to the technical field of preparation of benzoic acid derivatives. The invention particularly relates to a continuous production method of a benzoic acid derivative. The continuous reaction device is characterized by comprising a small-diameter sleeve, wherein the small-diameter sleeve is sleeved with a large-diameter sleeve, and a small pipeline is arranged between the small-diameter sleeve and the large-diameter sleeve, and a plurality of small holes are arranged on the small pipeline. The small-diameter casing is rotated, the large-diameter casing is fixed, and the reaction liquid composed of the nitric acid and the toluene derivative is between a small-diameter casing pipe and a large-diameter casing pipe.
Silver-catalyzed decarboxylative homocoupling reaction for the construction of tetrafluoroethylene-bridging aromatic compounds
Wang, Yong,Zhao, Huaxin,Xie, Xiaojuan,Jiang, Haizhen,Deng, Hongmei,Hao, Jian,Wan, Wen
supporting information, p. 2961 - 2970 (2019/08/22)
The Ag(I)-catalyzed decarboxylative homocoupling from the difluoroacetate has been developed to the synthesis of symmetric CF2–CF2 containing dimers. This radical dimerization overpasses the prefunctionalization of the substrate and provides a direct and efficient method for construction of tetrafluoroethylene bridge-linked homodimers.
A biocatalytic method for the chemoselective aerobic oxidation of aldehydes to carboxylic acids
Knaus, Tanja,Tseliou, Vasilis,Humphreys, Luke D.,Scrutton, Nigel S.,Mutti, Francesco G.
supporting information, p. 3931 - 3943 (2018/09/11)
Herein, we present a study on the oxidation of aldehydes to carboxylic acids using three recombinant aldehyde dehydrogenases (ALDHs). The ALDHs were used in purified form with a nicotinamide oxidase (NOx), which recycles the catalytic NAD+ at the expense of dioxygen (air at atmospheric pressure). The reaction was studied also with lyophilised whole cell as well as resting cell biocatalysts for more convenient practical application. The optimised biocatalytic oxidation runs in phosphate buffer at pH 8.5 and at 40 °C. From a set of sixty-one aliphatic, aryl-Aliphatic, benzylic, hetero-Aromatic and bicyclic aldehydes, fifty were converted with elevated yield (up to >99%). The exceptions were a few ortho-substituted benzaldehydes, bicyclic heteroaromatic aldehydes and 2-phenylpropanal. In all cases, the expected carboxylic acid was shown to be the only product (>99% chemoselectivity). Other oxidisable functionalities within the same molecule (e.g. hydroxyl, alkene, and heteroaromatic nitrogen or sulphur atoms) remained untouched. The reaction was scaled for the oxidation of 5-(hydroxymethyl)furfural (2 g), a bio-based starting material, to afford 5-(hydroxymethyl)furoic acid in 61% isolated yield. The new biocatalytic method avoids the use of toxic or unsafe oxidants, strong acids or bases, or undesired solvents. It shows applicability across a wide range of substrates, and retains perfect chemoselectivity. Alternative oxidisable groups were not converted, and other classical side-reactions (e.g. halogenation of unsaturated functionalities, Dakin-Type oxidation) did not occur. In comparison to other established enzymatic methods such as the use of oxidases (where the concomitant oxidation of alcohols and aldehydes is common), ALDHs offer greatly improved selectivity.
A mild method for synthesizing carboxylic acids by oxidation of aldoximes using hypervalent iodine reagents
Nakamura, Akira,Kanou, Hodaka,Tanaka, Junki,Imamiya, Akira,Maegawa, Tomohiro,Miki, Yasuyoshi
supporting information, p. 541 - 544 (2018/02/07)
A mild oxidation method for the conversion of aldoximes to carboxylic acids was developed mediated by hypervalent iodine reagents. This method covers a wide range of functionalized aldoximes and proceeds under mild conditions, utilizing PhI(OH)OTs as an oxidant.
Rational Design of Rod-Like Liquid Crystals Exhibiting Two Nematic Phases
Mandle, Richard J.,Cowling, Stephen J.,Goodby, John W.
supporting information, p. 14554 - 14562 (2017/10/23)
Recently, a polar, rod-like liquid-crystalline material was reported to exhibit two distinct nematic mesophases (termed N and NX) separated by a weakly first-order transition. Herein, we present our initial studies into the structure–property relationships that underpin the occurrence of the lower-temperature nematic phase, and report several new materials that exhibit this same transformation. We have prepared material with significantly enhanced temperature ranges, allowing us to perform a detailed study of both the upper- and lower-temperature nematic phases by using small-angle X-ray scattering. We observed a continuous change in d spacing rather than a sharp change at the phase transition, a result consistent with a transition between two nematic phases, structures of which are presumably degenerate.
Synthesis of Psoralidin derivatives and their anticancer activity: First synthesis of Lespeflorin I1
Pahari, Pallab,Saikia, Ujwal Pratim,Das, Trinath Prasad,Damodaran, Chendil,Rohr, Jürgen
supporting information, p. 3324 - 3334 (2016/05/19)
Synthetic scheme for the preparation of a number of different derivatives of anticancer natural product Psoralidin is described. A convergent synthetic approach is followed using simple starting materials like substituted phenyl acetic esters and benzoic acids. The developed synthetic route leads us to complete the first synthesis of an analogous natural product Lespeflorin I1, a mild melanin synthesis inhibitor. Preliminary bioactivity studies of the synthesized compounds are carried out against two commonly used prostate cancer cell lines. Results show that the bioactivity of the compounds can be manipulated by the simple modification of the functional groups.
Palladium on carbon-catalyzed aqueous transformation of primary alcohols to carboxylic acids based on dehydrogenation under mildly reduced pressure
Sawama, Yoshinari,Morita, Kosuke,Asai, Shota,Kozawa, Masami,Tadokoro, Shinsuke,Nakajima, Junichi,Monguchi, Yasunari,Sajiki, Hironao
supporting information, p. 1205 - 1210 (2015/04/22)
The catalytic dehydrogenation of alcohols to carbonyl products is a green sustainable oxidation with no production of waste except for hydrogen, which can be an energy source. Additionally, a reusable heterogeneous catalyst is valuable from the viewpoint of process chemistry and water is a green solvent. We have accomplished the palladium on carbon (Pd/C)-catalyzed dehydrogenation of primary alcohols to carboxylic acids in water under a mildly reduced pressure (800 hPa). The reduced pressure can be easily controlled by the vacuum controller of the rotary evaporator to remove the excess of generated hydrogen, which causes the reduction (reverse reaction) of aldehydes to alcohols (starting materials) and other undesirable side reactions. The present method is applicable to the reaction of various aliphatic and benzylic alcohols to the corresponding carboxylic acids, and the Pd/C could be reused at least 5 times.
Laccase-Mediator System for Alcohol Oxidation to Carbonyls or Carboxylic Acids: Toward a Sustainable Synthesis of Profens
Galletti, Paola,Pori, Matteo,Funiciello, Federica,Soldati, Roberto,Ballardini, Alberto,Giacomini, Daria
, p. 2684 - 2689 (2016/12/23)
By combining two green and efficient catalysts, such as the commercially available enzyme laccase from Trametes versicolor and the stable free radical 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), the oxidation in water of some primary alcohols to the corresponding carboxylic acids or aldehydes and of selected secondary alcohols to ketones can be accomplished. The range of applicability of bio-oxidation is widened by applying the optimized protocol to the oxidation of enantiomerically pure 2-arylpropanols (profenols) into the corresponding 2-arylpropionic acids (profens), in high yields and with complete retention of configuration.
Catalytic transformation of alcohols to carboxylic acid salts and H 2 using water as the oxygen atom source
Balaraman, Ekambaram,Khaskin, Eugene,Leitus, Gregory,Milstein, David
, p. 122 - 125 (2013/08/24)
The oxidation of alcohols to carboxylic acids is an important industrial reaction used in the synthesis of bulk and fine chemicals. Most current processes are performed by making use of either stoichiometric amounts of toxic oxidizing agents or the use of pressurized dioxygen. Here, we describe an alternative dehydrogenative pathway effected by water and base with the concomitant generation of hydrogen gas. A homogeneous ruthenium complex catalyses the transformation of primary alcohols to carboxylic acid salts at low catalyst loadings (0.2 mol%) in basic aqueous solution. A consequence of this finding could be a safer and cleaner process for the synthesis of carboxylic acids and their derivatives at both laboratory and industrial scales.
