538-43-2Relevant academic research and scientific papers
Copper-Catalyzed Decarboxylative Alkylselenation of Propiolic Acids with Se Powder and Epoxides
Yao, Yujing,Wang, Caihong,Ma, Yunfei,Zhang, Jintao,Sun, Dong,Chen, Luya,Huang, Lehao,Wu, Ge
, p. 1930 - 1934 (2021)
A copper-catalyzed decarboxylative alkylselenation of propiolic acids with Se powder and epoxides leading to alkynyl selenides is developed. This protocol not only provides an approach to obtain alkynyl selenides with the formation of double C?Se bonds, but also expands the applicability of alkynyl carboxylic acid. (Figure presented.).
An Amphiphilic (salen)Co Complex – Utilizing Hydrophobic Interactions to Enhance the Efficiency of a Cooperative Catalyst
Solís-Mu?ana, Pablo,Salam, Joanne,Ren, Chloe Z.-J.,Carr, Bronte,Whitten, Andrew E.,Warr, Gregory G.,Chen, Jack L.-Y.
supporting information, p. 3207 - 3213 (2021/06/01)
An amphiphilic (salen)Co(III) complex is presented that accelerates the hydrolytic kinetic resolution (HKR) of epoxides almost 10 times faster than catalysts from commercially available sources. This was achieved by introducing hydrophobic chains that increase the rate of reaction in one of two ways – by enhancing cooperativity under homogeneous conditions, and increasing the interfacial area under biphasic reaction conditions. While numerous strategies have been employed to increase the efficiency of cooperative catalysts, the utilization of hydrophobic interactions is scarce. With the recent upsurge in green chemistry methods that conduct reactions ‘on water’ and at the oil-water interface, the introduction of hydrophobic interactions has potential to become a general strategy for enhancing the catalytic efficiency of cooperative catalytic systems. (Figure presented.).
Ligand-Free Copper-Catalyzed Ullmann-Type C?O Bond Formation in Non-Innocent Deep Eutectic Solvents under Aerobic Conditions
Capriati, Vito,García-álvarez, Joaquín,Marinò, Manuela,Perna, Filippo M.,Quivelli, Andrea Francesca,Vitale, Paola
, (2021/12/09)
An efficient and novel protocol was developed for a Cu-catalyzed Ullmann-type aryl alkyl ether synthesis by reacting various (hetero)aryl halides (Cl, Br, I) with alcohols as active components of environmentally benign choline chloride-based eutectic mixtures. Under optimized conditions, the reaction proceeded under mild conditions (80 °C) in air, in the absence of additional ligands, with a catalyst [CuI or CuII species] loading up to 5 mol% and K2CO3 as the base, providing the desired aryloxy derivatives in up to 98 % yield. The potential application of the methodology was demonstrated in the valorization of cheap, easily available, and naturally occurring polyols (e. g., glycerol) for the synthesis of some pharmacologically active aryloxypropanediols (Guaiphenesin, Mephenesin, and Chlorphenesin) on a 2 g scale in 70–96 % yield. Catalyst, base, and deep eutectic solvent could easily and successfully be recycled up to seven times with an E-factor as low as 5.76.
Ultrasound Assisted the Synthesis of 1,3-Dioxolane Derivatives from the Reaction of Epoxides or 1,2-Diols with Various Ketones Using Graphene Oxide Catalyst
Mirza-Aghayan, Maryam,Mohammadi, Marzieh,Ahmadi, Zahra,Boukherroub, Rabah
, p. 2959 - 2969 (2020/04/22)
Abstract: The main objective of this study concerns the sonochemical synthesis of 1,3-dioxolane derivatives using graphene oxide catalyst by applying two methods. In the first method, we described the synthesis of 1,3-dioxolane by ring-opening of epoxides in the presence of ketones catalyzed by graphene oxide (GO) under ultrasonic irradiation. In the second sonochemical procedure, we described the synthesis of 1,3-dioxolane derivatives by the reaction of 1,2-diols with ketones using same GO catalyst. Mild reaction conditions, high yields, short reaction times, reusability of catalyst and easy isolation of the products make the developed methods very useful. Graphic Abstract: [Figure not available: see fulltext.]
Highly regio- and enantio-selective hydrolysis of two racemic epoxides by GmEH3, a novel epoxide hydrolase from Glycine max
Zhang, Chen,Li, Chuang,Zhu, Xiu-xiu,Liu, You-yi,Zhao, Jun,Wu, Min-chen
, p. 2795 - 2803 (2020/09/01)
A novel epoxide hydrolase from Glycine max, designated GmEH3, was excavated based on the computer-aided analysis. Then, gmeh3, a GmEH3-encoding gene, was cloned and successfully expressed in E. coli Rosetta(DE3). Among the ten investigated rac-epoxides, GmEH3 possessed the highest and best complementary regioselectivities (regioselectivity coefficients, αS = 93.7% and βR = 97.2%) in the asymmetric hydrolysis of rac-m-chlorostyrene oxide (5a), and the highest enantioselectivity (enantiomeric ratio, E = 55.6) towards rac-phenyl glycidyl ether (7a). The catalytic efficiency (kcatS/KmS = 2.50 mM?1 s?1) of purified GmEH3 for (S)-5a was slightly higher than that (kcatR/KmR = 1.52 mM?1 s?1) for (R)-5a, whereas the kcat/Km (5.16 mM?1 s?1) for (S)-7a was much higher than that (0.09 mM?1 s?1) for (R)-7a. Using 200 mg/mL wet cells of E. coli/gmeh3 as the biocatalyst, the scale-up enantioconvergent hydrolysis of 150 mM rac-5a at 25 °C for 1.5 h afforded (R)-5b with 90.2% eep and 95.4% yieldp, while the kinetic resolution of 500 mM rac-7a for 2.5 h retained (R)-7a with over 99% ees and 43.2% yields. Furthermore, the sources of high regiocomplementarity of GmEH3 for (S)- and (R)-5a as well as high enantioselectivity towards rac-7a were analyzed via molecular docking (MD) simulation.
MnIII Porphyrins: Catalytic Coupling of Epoxides with CO2 under Mild Conditions and Mechanistic Considerations
Milani, Jorge L. S.,Meireles, Alexandre M.,Bezerra, Werberson A.,Martins, Dayse. C. S.,Cangussu, Danielle,das Chagas, Rafael P.
, p. 4393 - 4402 (2019/08/01)
A series of 5,10,15,20-tetrakis(2,3-dichlorophenyl)porphyrinate complexes of manganese(III) [MnIII(T2,3DCPP)X] with six different axial ligands (X=NO3 ?, AcO?, IO3 ?, Br?, Cl?, HO?) were investigated as catalysts in the cycloaddition reactions of CO2 and styrene oxide (SO), under mild conditions, i. e., atmospheric pressure and 60 °C. [MnIIIT(2,3DCPP)IO3] showed the best catalytic performance, selectively producing the respective cyclic carbonate from diverse epoxides using tetrabutylammonium bromide as a nucleophile source. Mechanistic considerations were inferred from electronic spectra and spectrophotometric titrations, showing that there are a series of equilibriums involved in the formation of the catalytic active species. Stability constants for the proposed equilibrium models were determined using SQUAD software. A catalytic cycle has been proposed based on those observations.
A novel homochiral metal-organic framework with an expanded open cage based on (: R)-3,3′-bis(6-carboxy-2-naphthyl)-2,2′-dihydroxy-1,1′-binaphthyl: synthesis, X-ray structure and efficient HPLC enantiomer separation
Tanaka, Koichi,Kawakita, Tomohiro,Morawiak, Maja,Urbanczyk-Lipkowska, Zofia
, p. 487 - 493 (2019/01/21)
A new homochiral metal-organic framework (MOF) with an expanded open cage based on the (R)-3,3′-bis(6-carboxy-2-naphthyl)-2,2′-dihydroxy-1,1′-binaphthyl ligand was synthesized and utilized as a novel chiral stationary phase for high-performance liquid chromatography. Twelve racemates including sec-alcohols, sulfoxides, epoxides, lactone, 1,3-dioxolan-2-one, and oxazolidinone were used as analytes for evaluating the separation properties of the chiral-MOF-packed column. Experimentally, the homochiral MOF offered good molecular recognition ability, which suggests good prospects for the application of chiral MOFs as stationary phases for enantioseparation.
Enantioselective Resolution Copolymerization of Racemic Epoxides and Anhydrides: Efficient Approach for Stereoregular Polyesters and Chiral Epoxides
Li, Jie,Ren, Bai-Hao,Wan, Zhao-Qian,Chen, Shi-Yu,Liu, Ye,Ren, Wei-Min,Lu, Xiao-Bing
supporting information, p. 8937 - 8942 (2019/06/11)
Herein we report an efficient strategy for preparing isotactic polyesters and chiral epoxides via enantioselective resolution copolymerization of racemic terminal epoxides with anhydrides, mediated by enantiopure bimetallic complexes in conjunction with a nucleophilic cocatalyst. The chirality of both the axial linker and the diamine backbones of the ligand are responsible for the chiral induction of this kinetic resolution copolymerization process. The catalyst systems exhibit exceptional levels of enantioselectivity with a kinetic resolution coefficient exceeding 300 for various racemic epoxides, affording highly isotactic copolymers (selectivity factors of more than 300) with a completely alternating structure and low polydispersity index. Most of the produced isotactic polyesters are typical semicrystalline materials with melting temperatures in the range from 77 to 160 °C.
An innovative synthesis pathway to benzodioxanes: The peculiar reactivity of glycerol carbonate and catechol
Tabanelli,Giliberti,Mazzoni,Cucciniello,Cavani
, p. 329 - 338 (2019/01/28)
A peculiar reactivity of glycerol carbonate (GlyC) as an innovative and highly reactive alkylating agent for phenolic compounds is investigated in this article. In particular, 2-hydroxymethyl-1,4-benzodioxane (HMB), a key intermediate for the pharmaceutical industry, has been selectively synthesized by the reaction of a slight excess of GlyC with catechol in the presence of a basic catalyst (NaOCH3, Na-mordenite, MgO), without requiring a reaction solvent. Both reagents have been quantitatively converted in just one hour at 170 °C with a HMB yield, up to 88%, in the presence of a homogeneous basic catalyst (NaOCH3). Notably, the main side product, the HMB isomer, may be an interesting intermediate for the synthesis of calone analogues, which are important scaffolds used in fragrances. A detailed mechanistic study, supported by kinetics, GC-MS, and HMBC NMR characterization, is also reported. Accordingly, this paper describes a completely innovative and greener synthesis pathway to benzodioxanes.
HETEROCYCLIC LIPXON ANALOGS AND USES THEROF
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Page/Page column 103, (2018/03/09)
The present invention relates to a compound of formula (I): wherein L is an optionally substituted heterocyclic group excluding unsubstituted monocyclic pyridine groups; wherein a is 0, 1 or 2; wherein R1 is H or with R2 is a bond; wherein R2 is an optionally substituted alkoxy or aryloxy group, or with R1 forms a bond; wherein R3 is an optionally substituted alkyl group; and wherein R4 is CH2, CMe2 or O. Such compounds may be used in the treatment or prophylaxis of a disease or condition in which inhibition of acute inflammation and/or promotion of its resolution and/or suppression of fibrosis.
