80137-66-2Relevant academic research and scientific papers
Lipase catalysed oxidations in a sugar-derived natural deep eutectic solvent
Vagnoni, Martina,Samorì, Chiara,Pirini, Daniele,Vasquez De Paz, Maria Katrina,Gidey, Dawit Gebremichael,Galletti, Paola
, (2021/05/06)
Chemoenzymatic oxidations involving the CAL-B/H2O2 system was developed in a sugar derived Natural Deep Eutectic Solvent (NaDES) composed by a mixture of glucose, fructose and sucrose. Good to excellent conversions of substrates like cyclooctene, limonene, oleic acid and stilbene to their corresponding epoxides, cyclohexanone to its corresponding lactone and 2-phenylacetophenone to its corresponding ester, demonstrate the viability of the sugar NaDES as a reaction medium for epoxidation and Baeyer-Villiger oxidation.
Green Oxidation of Ketones to Lactones with Oxone in Water
Bertolini, Valentina,Appiani, Rebecca,Pallavicini, Marco,Bolchi, Cristiano
, p. 15712 - 15716 (2021/11/01)
Cyclic ketones were quickly and quantitatively converted to 5-, 6-, and 7-membered lactones, very important synthons, by treatment with Oxone, a cheap, stable, and nonpollutant oxidizing reagent, in 1 M NaH2PO4/Na2HPO4 water solution (pH 7). Under such simple and green conditions, no hydroxyacid was formed, thus making the adoption of more complex and non-eco-friendly procedures previously developed to avoid lactone hydrolysis unnecessary. With some changes, the method was successfully applied also to water-insoluble ketones such as adamantanone, acetophenone, 2-indanone, and the challenging cycloheptanone.
Revisiting Alkane Hydroxylation with m-CPBA (m-Chloroperbenzoic Acid) Catalyzed by Nickel(II) Complexes
Itoh, Mayu,Itoh, Shinobu,Kubo, Minoru,Morimoto, Yuma,Shinke, Tomoya,Sugimoto, Hideki,Wada, Takuma,Yanagisawa, Sachiko
, p. 14730 - 14737 (2021/09/29)
Mechanistic studies are performed on the alkane hydroxylation with m-CPBA (m-chloroperbenzoic acid) catalyzed by nickel(II) complexes, NiII(L). In the oxidation of cycloalkanes, NiII(TPA) acts as an efficient catalyst with a high yield and a high alcohol selectivity. In the oxidation of adamantane, the tertiary carbon is predominantly oxidized. The reaction rate shows first-order dependence on [substrate] and [NiII(L)] but is independent on [m-CPBA]; vobs=k2[substrate][NiII(L)]. The reaction exhibited a relatively large kinetic deuterium isotope effect (KIE) of 6.7, demonstrating that the hydrogen atom abstraction is involved in the rate-limiting step of the catalytic cycle. Furthermore, NiII(L) supported by related tetradentate ligands exhibit apparently different catalytic activity, suggesting contribution of the NiII(L) in the catalytic cycle. Based on the kinetic analysis and the significant effects of O2 and CCl4 on the product distribution pattern, possible contributions of (L)NiII?O. and the aroyloxyl radical as the reactive oxidants are discussed.
Selective Aerobic Oxidation of Secondary C (sp3)-H Bonds with NHPI/CAN Catalytic System
Wang, Lingyao,Zhang, Yuanbin,Yuan, Haoran,Du, Renfeng,Yao, Jia,Li, Haoran
, p. 1663 - 1669 (2020/10/21)
Abstract: The direct aerobic oxidation of secondarty C(sp3)-H bonds was achieved in the presence of N-hydroxyphthalimide (NHPI) and cerium ammonium nitrate (CAN) under mild conditions. Various benzylic methylenes could be oxidized to carbonyl compounds in satisfied selectivity while saturated cyclic alkanes could be further oxidized to the corresponding lactones with the catalytic system. Remarkably, 25% of isochroman was converted to corresponding ketone with a selectivity of 96%. The reaction was initiated by hydrogen atom abstraction from NHPI by cerium and nitrates under oxygen atmosphere to form PINO radicals. 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) addition experiments showed that the oxidation proceeded via a complex radical chain mechanism and an ion pathway. Graphic Abstract: [Figure not available: see fulltext.]
Aliphatic C–H hydroxylation activity and durability of a nickel complex catalyst according to the molecular structure of the bis(oxazoline) ligands
Hikichi, Shiro,Izumi, Takashi,Matsuba, Naki,Nakazawa, Jun
, (2021/07/13)
Applicability of the oxazoline-based compounds, bis(2-oxazolynyl)methane (BOX) and 2,6-bis(2-oxazolynyl)pyridine (PyBOX), as supporting ligands of nickel(II) complexes for the catalysis of aliphatic C–H hydroxylation with m-CPBA (meta-chloroperoxybenzoic acid) was explored. Substituent groups at the fourth and fifth positions of oxazoline rings and the bridgehead carbon atom of the BOX derivatives affected the catalytic performances toward cyclohexane hydroxylation. Presence of dioxygen led to a reduced catalytic performance of the nickel complexes, except in the case of a fully substituted BOX ligand complex.
Kinetics Modeling of a Convergent Cascade Catalyzed by Monooxygenase-Alcohol Dehydrogenase Coupled Enzymes
Bornscheuer, Uwe T.,Engel, Jennifer,Kara, Selin
supporting information, p. 411 - 420 (2020/12/22)
A convergent cascade reaction coupling a cyclohexanone monooxygenase variant and an alcohol dehydrogenase to make ?-caprolactone from cyclohexanone and 1,6-hexanediol was characterized via progress curve analysis with two kinetic models developed iteratively. A chemical side reaction occurring with the utilized Tris buffer and consequent byproduct formations were considered in Model 2, which reduced the root-mean-square error (RMSE) values by half, compared to Model 1 (RMSE values of 13%-40%). The optimized model, Model 2, led us to simulate the cascade reaction including 22 kinetic parameters with a maximum RMSE value in the range of 10%-21%.
Method for preparing epsilon-caprolactone, 6-hydroxyhexanoic acid and esters thereof from tetrahydrofuranacetic acid and esters thereof
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Paragraph 0005; 0024, (2021/05/29)
The invention provides a method for preparing epsilon-caprolactone and 6-hydroxyhexanoic acid and esters thereof from tetrahydrofuranacetic acid and esters thereof, which comprises the following steps: in a solvent, in a reducing atmosphere and under the action of a catalyst, carrying out reduction reaction on tetrahydrofuranacetic acid and ester compounds thereof under the conditions that the pressure is 0.1-10MPa and the temperature is 20-200 DEG C for 0.5-48 hours, separating the catalyst, and distilling out the solvent, so that the target products epsilon-caprolactone, 6-hydroxyhexanoic acid and ester compounds of 6-hydroxyhexanoic acid are obtained. According to the method, efficient conversion of bio-based tetrahydrofuranacetic acid and esters thereof is realized under relatively mild conditions, the produced epsilon-caprolactone and 6-hydroxycaproic acid and ester compounds thereof are polymer monomers and are wide in application, and the application range of biomass is expanded; and meanwhile, the dilemma that the preparation of [epsilon]-caprolactone, 6-hydroxycaproic acid and ester thereof must depend on fossil resources is solved.
A Polyketide Cyclase That Forms Medium-Ring Lactones
Gao, De-Wei,Jamieson, Cooper S.,Wang, Gaoqian,Yan, Yan,Zhou, Jiahai,Houk,Tang, Yi
, p. 80 - 84 (2021/01/13)
Medium-ring lactones are synthetically challenging due to unfavorable energetics involved in cyclization. We have discovered a thioesterase enzyme DcsB, from the decarestrictine C1 (1) biosynthetic pathway, that efficiently performs medium-ring lactonizations. DcsB shows broad substrate promiscuity toward linear substrates that vary in lengths and substituents, and is a potential biocatalyst for lactonization. X-ray crystal structure and computational analyses provide insights into the molecular basis of catalysis.
PROCESS FOR PRODUCING HYDROXY ACID
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Paragraph 0025-0027, (2020/05/13)
PROBLEM TO BE SOLVED: To provide a process for highly efficiently producing hydroxy acid from cyclic ketone. SOLUTION: Provided is a process for producing hydroxy acid, including a step in which hydrogen peroxide and cyclic ketone are reacted using water as solvent in the presence of a zeolite catalyst and a catalytic amount of organic acid. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
Efficient alkane hydroxylation catalysis of nickel(ii) complexes with oxazoline donor containing tripodal tetradentate ligands
Hikichi, Shiro,Horii, Sena,Nakazawa, Jun,Okamura, Masaya,Terao, Ikumi
supporting information, p. 6108 - 6118 (2020/05/25)
Tris(oxazolynylmethyl)amine TOAR(where R denotes the substituent groups on the fourth position of the oxazoline rings) complexes of nickel(ii) have been synthesized as catalyst precursors for alkane oxidation withmeta-chloroperoxybenzoic acid (m-CPBA). The molecular structures of acetato, nitrato,meta-chlorobenzoato and chlorido complexes with TOAMe2have been determined using X-ray crystallography. The bulkiness of the substituent groups R affects the coordination environment of the nickel(ii) centers, as has been demonstrated by comparison of the molecular structures of chlorido complexes with TOAMe2and TOAtBu. The nickel(ii)-acetato complex with TOAMe2is an efficient catalyst precursor compared with the tris(pyridylmethyl)amine (TPA) analogue. Oxazolynyl donors’ strong s-electron donating ability will enhance the catalytic activity. Catalytic reaction rates and substrate oxidizing position selectivity are controlled by the structural properties of the R of TOAR. Reaction of the acetato complex with TOAMe2andm-CPBA yields the corresponding acylperoxido species, which can be detected using spectroscopy. Kinetic studies of the decay process of the acylperoxido species suggest that the acylperoxido species is a precursor of an active species for alkane oxidation.
