2306-88-9Relevant articles and documents
Oxoammonium salts. 9. Oxidative dimerization of polyfunctional primary alcohols to esters. An interesting β oxygen effect
Merbouh, Nabyl,Bobbitt, James M.,Brueckner, Christian
, p. 5116 - 5119 (2004)
The use of the oxidant 4-acetylamino-2,2,6,6-tetramethylpiperidine-1- oxoammonium tetrafluoroborate in combination with pyridine for the oxidative, dimeric esterification of primary alcohols is described. The ester is the predominant product of the reaction with alcohols containing a β oxygen. In the absence of a β oxygen, the corresponding aldehyde is found in appreciable amounts, but a concentration effect can be observed. In the absence of pyridine, little ester is formed, and no appreciable reaction takes place with β-oxygenated compounds. δ Lactones have been prepared from diethylene glycol and 2,2′-thiodiethanol, without sulfur oxidation.
Green Oxidation of n-Octanol on Supported Nanogold Catalysts: Formation of Gold Active Sites under Combined Effect of Gold Content, Additive Nature and Redox Pretreatment
Pakrieva,Kolobova,Mamontov,Bogdanchikova,Farias,Pascual,Cortés Corberán,Martinez Gonzalez,Carabineiro,Pestryakov
, p. 1615 - 1624 (2019)
The combined influence of gold content (0.5 or 4 wt. %), modifying additives (La or Ce oxides) and redox pretreatments (H2 or O2) on catalytic properties and formation of active sites of Au/TiO2 in the selective oxidation of n-octanol under mild conditions was studied. Samples were characterized by BET, XRD, EDX, ICP, TEM, STEM-HAADF, CO2-TPD, H2-TPR and XPS methods. The order of catalytic activity depended on the support nature for all treated samples, as follows: Au/La2O3/TiO2>Au/CeO2/TiO2>Au/TiO2. The catalytic activity enhanced with the increase of gold loading in the samples with hydrogen pretreatment, while after the oxidative pretreatment of the catalysts the opposite dependence of the activity with the gold content was found. This catalytic behavior was explained by a change in the surface concentration of monovalent gold ions, which seemed to be the active sites. The most active catalyst, 0.5 % Au/La2O3/TiO2, pretreated in oxidative atmosphere, had the highest surface concentration of monovalent gold ions.
Cloning, overexpression, and characterization of a novel organic solvent-tolerant lipase from Paenibacillus pasadenensis CS0611
Gao, Jiaxin,Ou, Xiaoyang,Xu, Pei,Zong, Minhua,Lou, Wenyong
, p. 937 - 945 (2018)
We found a novel lipase gene in the Paenibacillus pasadenensis CS0611 strain. The lipase gene sequence was cloned into the pET-28a expression vector to construct a recombinant lipase protein containing 6 × His tags at the C- and N-termini, respectively. High-level expression of the lipase in E.coli BL21 (DE3) was obtained upon induction with IPTG at 20 °C. The recombinant lipase activity was approximately 1631-fold higher than the wild type. His-tagged recombinant lipase was purified rapidly and efficiently by using Ni-charged affinity chromatography with 63.5% recovery and a purification factor of 10.78. The purified lipase was stable in a broad range of temperatures and pH values, with the optimal temperature and pH being 50 °C and 7.0, respectively. Its activity was stimulated to different degrees in the presence of metal ions such as Ca2+, Mg2+, and some non-ionic surfactants. In addition, the purified lipase was activated by a series of water-miscible organic solvents such as some short carbon chain alcohols and was highly tolerant to some water-immiscible organic solvents.
Dehydrogenative alcohol coupling and one-pot cross metathesis/dehydrogenative coupling reactions of alcohols using Hoveyda-Grubbs catalysts
?zer, Halenur,Arslan, Dilan,?ztürk, Bengi ?zgün
, p. 5992 - 6000 (2021/04/12)
In this study,in situformed ruthenium hydride species that were generated from Grubbs type catalysts are used as efficient catalysts for dehydrogenative alcohol coupling and sequential cross-metathesis/dehydrogenative coupling reactions. The selectivity of Grubbs first generation catalysts (G1) in dehydrogenative alcohol coupling reactions can be tuned for the ester formation in the presence of weak bases, while the selectivity can be switched to the β-alkylated alcohol formation using strong bases. The performance of Hoveyda-Grubbs 2nd generation catalyst (HG2) was improved in the presence of tricyclohexylphosphine for the selective synthesis of ester derivatives with weak and strong bases in quantitative yields. Allyl alcohol was used as self and cross-metathesis substrate for the HG2 catalyzed sequential cross-metathesis/dehydrogenative alcohol coupling reactions to obtain γ-butyrolactone and long-chain ester derivatives in quantitative yields.
Carboxylic Acid Reductase Can Catalyze Ester Synthesis in Aqueous Environments
Pongpamorn, Pornkanok,Kiattisewee, Cholpisit,Kittipanukul, Narongyot,Jaroensuk, Juthamas,Trisrivirat, Duangthip,Maenpuen, Somchart,Chaiyen, Pimchai
supporting information, p. 5749 - 5753 (2021/02/01)
Most of the well-known enzymes catalyzing esterification require the minimization of water or activated substrates for activity. This work reports a new reaction catalyzed by carboxylic acid reductase (CAR), an enzyme known to transform a broad spectrum of carboxylic acids into aldehydes, with the use of ATP, Mg2+, and NADPH as co-substrates. When NADPH was replaced by a nucleophilic alcohol, CAR from Mycobacterium marinum can catalyze esterification under aqueous conditions at room temperature. Addition of imidazole, especially at pH 10.0, significantly enhanced ester production. In comparison to other esterification enzymes such as acyltransferase and lipase, CAR gave higher esterification yields in direct esterification under aqueous conditions. The scalability of CAR catalyzed esterification was demonstrated for the synthesis of cinoxate, an active ingredient in sunscreen. The CAR esterification offers a new method for green esterification under high water content conditions.
