110-19-0Relevant articles and documents
Synthesis of a novel multi-SO3H functionalized ionic liquid and its catalytic activities
Xudong, Sun,Huiquan, Xiao,Yijun, Du,Jingjing, Zhang,Xuezheng, Liang,Chenze, Qi
, p. 301 - 305 (2012)
A novel multi-SO3H functionalized ionic liquid is synthesized and a detailed account of its cata- lytic activities in acetalization and acetylation is given. The results showed that the ionic liquid is very efficient in the conventional acid-catalyzed reactions with good to excellent yields within a short reaction time. Oper- ational simplicity, small amounts required, low cost of the catalyst, high yields, scalability and reusability are the key features of this methodology, which indicates the high potentialities of the novel ionic liquid to be used in environmentally friendly processes. Pleiades Publishing, Ltd., 2012.
The dual role of micelles as templates and reducing agents for the fabrication of catalytically active hollow silver nanospheres
Sasidharan, Manickam,Senthil, Chenrayan,Kumari, Vandana,Bhaumik, Asim
, p. 733 - 736 (2015)
We report a simple and efficient protocol for fabrication of colloidal hollow silver nanospheres of size less than 30 nm using an ABC triblock copolymer poly(styrene-b-vinyl-2-pyridine-b-ethylene oxide) in the absence of any reducing agents. The colloidal silver hollow nanoparticles serve as an efficient heterogeneous catalyst for Baeyer-Villiger oxidation of ketones to the corresponding lactones in the presence of anhydrous tert-butylhydroperoxide under liquid-phase conditions.
Preparation of clay-supported Sn catalysts and application to Baeyer-Villiger oxidation
Hara, Takayoshi,Hatakeyama, Moriaki,Kim, Arum,Ichikuni, Nobuyuki,Shimazu, Shogo
, p. 771 - 777 (2012)
Clay-intercalated Sn catalysts were prepared by a conventional cation-exchange method and used for the Baeyer-Villiger oxidation of various ketones with hydrogen peroxide as an oxidant. The intercalation of monomeric Sn species into the clay interlayer was monitored by solid-state 7Li MAS NMR. Solid-state 119Sn MAS NMR and Sn K-edge XAFS analysis revealed that an isolated Sn species, such as [SnIV(OH)x(H 2O)5-x](4-x)+ (x = 0-3), was formed in the clay interlayers. Our clay-intercalated Sn catalysts showed extremely high performance in Bayer-Villiger oxidation and were also reusable without any significant loss of activity or selectivity. The Royal Society of Chemistry 2012.
Green, efficient and economical coal fly ash based phosphomolybdic acid catalysts: preparation, characterization and application
Malpani, Sakshi Kabra,Goyal, Deepti,Katara, Stuti,Rani, Ashu
, p. 3017 - 3034 (2021/02/26)
Abstract: Cost-effective, efficient and green solid acid catalysts have been synthesized by incipient wetness impregnation of various weight fractions of phosphomolybdic acid (5, 10, 15 and 25 wt. %) on mechanically and thermally activated coal fly ash. N2 adsorption–desorption, XRD, FT-IR, SEM, SEM–EDX, TEM, TGA, UV–Vis DRS, solid state 31P MAS NMR were used for characterization of as synthesized catalysts. Catalytic active sites were developed on inert surface of coal fly ash by using various activation techniques whose performance was assessed over a series of acylation of various aliphatic alcohols. For rapid and higher catalytic activity, reactions were conducted in microwave heating mode. Impregnation of phosphomolybdic acid generates Lewis acidic sites on coal fly ash surface as inferred by pyridine adsorbed FT-IR studies which were then utilized in acylation reactions. Various reaction parameters like weight fraction of catalysts, molar ratio of reactants, time, temperature, etc. were optimized for attaining highest conversion %. The catalyst with 15 wt. % of phosphomolybdic acid was found to be more efficient and could be recycled up to five reaction cycles with analogous conversion %. Negligible leaching of catalyst was confirmed by hot filtration test. This work suggests an alternative approach for valorisation of industrial solid waste, coal fly ash in development of innovative, economical solid catalysts. Graphic abstract: [Figure not available: see fulltext.].
Synthesis, Characterisation, and Determination of Physical Properties of New Two-Protonic Acid Ionic Liquid and its Catalytic Application in the Esterification
Shahnavaz, Zohreh,Zaharani, Lia,Khaligh, Nader Ghaffari,Mihankhah, Taraneh,Johan, Mohd Rafie
, p. 165 - 172 (2020/10/26)
A new ionic liquid was synthesised, and its chemical structure was elucidated by FT-IR, 1D NMR, 2D NMR, and mass analyses. Some physical properties, thermal behaviour, and thermal stability of this ionic liquid were investigated. The formation of a two-protonic acid salt namely 4,4′-trimethylene-N,N′-dipiperidinium sulfate instead of 4,4′-trimethylene-N,N′-dipiperidinium hydrogensulfate was evidenced by NMR analyses. The catalytic activity of this ionic liquid was demonstrated in the esterification reaction of n-butanol and glacial acetic acid under different conditions. The desired acetate was obtained in 62-88 % yield without using a Dean-Stark apparatus under optimal conditions of 10 mol-% of the ionic liquid, an alcohol to glacial acetic acid mole ratio of 1.3: 1.0, a temperature of 75-100°C, and a reaction time of 4 h. α-Tocopherol (α-TCP), a highly efficient form of vitamin E, was also treated with glacial acetic acid in the presence of the ionic liquid, and O-acetyl-α-tocopherol (Ac-TCP) was obtained in 88.4 % yield. The separation of esters was conducted during workup without the utilisation of high-cost column chromatography. The residue and ionic liquid were used in subsequent runs after the extraction of desired products. The ionic liquid exhibited high catalytic activity even after five runs with no significant change in its chemical structure and catalytic efficiency.
Evaluation of gem-Diacetates as Alternative Reagents for Enzymatic Regio-and Stereoselective Acylation of Alcohols
Koszelewski, Dominik,Brodzka, Anna,Madej, Arleta,Trzepizur, Damian,Ostaszewski, Ryszard
, p. 6331 - 6342 (2021/05/06)
Geminal diacetates have been used as sustainable acyl donors for enzymatic acylation of chiral and nonchiral alcohols. Especially, it was revealed that geminal diacetates showed higher reactivity than vinyl acetate for hydrolases that are sensitive to acetaldehyde. Under optimized conditions for enzymatic acylation, several synthetically relevant saturated and unsaturated acetates of various primary alcohols were obtained in very high yields up to 98% without E/Z isomerization of the double bond. Subsequently, the acyl donor was recreated from the resulting aldehyde and reused constantly in acylation. Therefore, the developed process is characterized by high atomic efficiency. Moreover, it was shown that acylation using geminal diacetates resulted in remarkable regioselectivity by discriminating among the primary and secondary hydroxyl groups in 1-phenyl-1,3-propanediol providing exclusively 3-acetoxy-1-phenyl-propan-1-ol in good yield. Further, enzymatic kinetic resolution (EKR) and chemoenzymatic dynamic kinetic resolution (DKR) protocols were developed using geminal diacetate as an acylating agent, resulting in chiral acetates in high yields up to 94% with enantiomeric excesses exceeding 99%.
Genome mining reveals new bacterial type I Baeyer-Villiger monooxygenases with (bio)synthetic potential
Bianchi, Dario A.,Carabajal, María Ayelén,Ceccoli, Romina D.,Rial, Daniela V.
, (2020/03/19)
Baeyer-Villiger monooxygenases (BVMOs) are oxidorreductases that catalyze the oxidation of ketones in a very selective manner. By genome mining we detected seven putative type I BVMOs in Bradyrhizobium diazoefficiens USDA 110. As we established the phylogenetic relationships among them and with other type I BVMOs, we found out that they belong to different clades of the phylogenetic tree. Thus, we decided to clone and heterologously express five of them. Three of them, each one from a divergent phylogenetic group, were obtained as soluble proteins, allowing us to proceed with their biocatalytic assessment and enzymatic characterization. As to substrate scope and selectivity, we observed a complementary behavior among the three BVMOs. BVMO2 was the more versatile biocatalyst in whole-cell systems while BVMO4 and BVMO5 showed a narrow substrate profile with preference for linear ketones and particular regioselectivity for (±)-cis-bicyclo[3.2.0]hept-2-en-6-one.
Enzyme-Catalyzed Synthesis of Esters in Water
Mestrom, Luuk,Claessen, Jord G. R.,Hanefeld, Ulf
, p. 2004 - 2010 (2019/04/14)
MsAcT catalyzes the esterification of primary alcohols in water. When utilizing acid and alcohol as starting materials low yields dictated by thermodynamics were observed. However, with activated esters such as ethyl acetate and vinyl acetate very high yields of the desired ester can be achieved in combination with the appropriate alcohol. This study investigated both the intrinsic kinetic properties of MsAcT for the hydrolysis and transesterification of esters in water as well as the thermodynamics of the reaction. In comparison to the chemical or enzymatic ester synthesis using either toxic reagent, and harsh organic solvents, the MsAcT-catalyzed synthesis of esters of primary alcohols can be achieved efficiently in water without neutralization steps.
Ester Synthesis in Water: Mycobacterium smegmatis Acyl Transferase for Kinetic Resolutions
de Leeuw, Nicolas,Torrelo, Guzman,Bisterfeld, Carolin,Resch, Verena,Mestrom, Luuk,Straulino, Emanuele,van der Weel, Laura,Hanefeld, Ulf
, p. 242 - 249 (2017/11/16)
The acyl transferase from Mycobacterium smegmatis (MsAcT) catalyses transesterification reactions in aqueous media because of its hydrophobic active site. Aliphatic cyanohydrin and alkyne esters can be synthesised in water with excellent and strikingly opposite enantioselectivity [(R);E>37 and (S);E>100, respectively]. When using this enzyme, the undesired hydrolysis of the acyl donor is an important factor to take into account. Finally, the choice of acyl donor can significantly influence the obtained enantiomeric excesses. (Figure presented.).
Total Synthesis and Functional Evaluation of Fourteen Derivatives of Lysocin E: Importance of Cationic, Hydrophobic, and Aromatic Moieties for Antibacterial Activity
Kaji, Takuya,Murai, Motoki,Itoh, Hiroaki,Yasukawa, Jyunichiro,Hamamoto, Hiroshi,Sekimizu, Kazuhisa,Inoue, Masayuki
supporting information, p. 16912 - 16919 (2016/11/16)
Lysocin E (1) is a structurally complex 37-membered depsipeptide comprising 12 amino-acid residues with an N-methylated amide and an ester linkage. Compound 1 binds to menaquinone (MK) in the bacterial membrane to exert its potent bactericidal activity. To decipher the biologically important functionalities within this unique antibiotic, we performed a comprehensive structure-activity relationship (SAR) study by systematically changing the side-chain structures of l-Thr-1, d-Arg-2, N-Me-d-Phe-5, d-Arg-7, l-Glu-8, and d-Trp-10. First, we achieved total synthesis of the 14 new side-chain analogues of 1 by employing a solid-phase strategy. We then evaluated the MK-dependent liposomal disruption and antimicrobial activity against Staphylococcus aureus by 1 and its analogues. Correlating data between the liposome and bacteria experiments revealed that membrane lysis was mainly responsible for the antibacterial functions. Altering the cationic guanidine moiety of d-Arg-2/7 to a neutral amide, and the C7-acyl group of l-Thr-1 to the C2 or C11 counterpart decreased the antimicrobial activities four- or eight-fold. More drastically, chemical mutation of d-Trp-10 to d-Ala-10 totally abolished the bioactivities. These important findings led us to propose the biological roles of the side-chain functionalities.
