6493-77-2Relevant academic research and scientific papers
Kinetic Resolution of Nearly Symmetric 3-Cyclohexene-1-carboxylate Esters Using a Bacterial Carboxylesterase Identified by Genome Mining
Dou, Zhe,Chen, Xuanzao,Niwayama, Satomi,Xu, Guochao,Ni, Ye
supporting information, p. 3043 - 3047 (2021/05/05)
A new bacterial carboxylesterase (CarEst3) was identified by genome mining and found to efficiently hydrolyze racemic methyl 3-cyclohexene-1-carboxylate (rac-CHCM) with a nearly symmetric structure for the synthesis of (S)-CHCM. CarEst3 displayed a high substrate tolerance and a stable catalytic performance. The enantioselective hydrolysis of 4.0 M (560 g·L-1) rac-CHCM was accomplished, yielding (S)-CHCM with a >99% ee, a substrate to catalyst ratio of 1400 g·g-1, and a space-time yield of 538 g·L-1·d-1.
Ruthenium complex immobilized on supported ionic-liquid-phase (SILP) for alkoxycarbonylation of olefins with CO2
Xia, Shi-Ping,Ding, Guang-Rong,Zhang, Rui,Han, Li-Jun,Xu, Bao-Hua,Zhang, Suo-Jiang
, p. 3073 - 3080 (2021/05/05)
In this study, the heterogeneously catalyzed alkoxycarbonylation of olefins with CO2based on a supported ionic-liquid-phase (SILP) strategy is reported for the first time. An [Ru]@SILP catalyst was accessed by immobilization of ruthenium complex on a SILP, wherein imidazolium chloride was chemically integrated at the surface or in the channels of the silica gel support. An active Ru site was generated through reacting Ru3(CO)12with the decorated imidazolium chloride in a proper microenvironment. Different IL films, by varying the functionality of the side chain at the imidazolium cation, were found to strongly affect the porosity, active Ru sites, and CO2adsorption capacity of [Ru]@SILP, thereby considerably influencing its catalytic performance. The optimized [Ru]@SILP-A-2 displayed enhanced catalytic performance and prominent substrate selectivity compared to an independent homogeneous system under identical conditions. These findings provide the basis for a novel design concept for achieving both efficient and stable catalysts in the coupling of CO2with olefins.
Protection of COOH and OH groups in acid, base and salt free reactions
Zhu, Xiaotao,Qian, Bo,Wei, Rongbiao,Huang, Jian-Dong,Bao, Hongli
supporting information, p. 1444 - 1447 (2018/04/12)
We report an iron-catalyzed general functional group protection method with inexpensive reagents. This environmentally benign process does not use acids or bases, and does not produce waste products. Further purification beyond filtration and evaporation is, in most cases, unnecessary. Free COOH and OH groups can be protected in a one-pot reaction.
A Selective and Functional Group-Tolerant Ruthenium-Catalyzed Olefin Metathesis/Transfer Hydrogenation Tandem Sequence Using Formic Acid as Hydrogen Source
Zieliński, Grzegorz K.,Majtczak, Jaros?awa,Gutowski, Maciej,Grela, Karol
, p. 2542 - 2553 (2018/03/09)
A ruthenium-catalyzed transfer hydrogenation of olefins utilizing formic acid as a hydrogen donor is described. The application of commercially available alkylidene ruthenium complexes opens access to attractive C(sp3)-C(sp3) bond formation in an olefin metathesis/transfer hydrogenation sequence under tandem catalysis conditions. High chemoselectivity of the developed methodology provides a remarkable synthetic tool for the reduction of various functionalized alkenes under mild reaction conditions. The developed methodology is applied for the formal synthesis of the drugs pentoxyverine and bencyclane.
Enantioselective Diels-Alder Reactions of Carboxylic Ester Dienophiles Catalysed by Titanium-Based Chiral Lewis Acid
Choughule, Yogesh K.,Patwardhan, Anand V.
, p. 921 - 926 (2016/07/06)
A new titanium-based chiral Lewis acid 1 has been developed using (1R,2R)-1,2-bis-(2-methoxyphenyl)-ethane-1,2-diol as a chiral vicinal diol ligand. This chiral catalyst was found to exhibit uniformly high enantioselectivity towards carboxylic ester dienophiles in Diels-Alder reactions. The chiral vicinal ligand (1R,2R)-1,2-bis-(2-methoxyphenyl)-ethane-1,2-diol is inexpensive and is easily accessible.
Solvent-free Diels-Alder reaction in a closed batch system
Sun, Daolai,Sato, Fumiya,Yamada, Yasuhiro,Sato, Satoshi
, p. 276 - 282 (2013/05/08)
Solvent-free Diels-Alder reactions were carried out by heating a mixture of a volatile diene, such as 1,3-butadiene, isoprene, or 2,3-dimethyl-1,3- butadiene, and a dienophile, such as methyl vinyl ketone, methyl acrylate, or maleic anhydride, in a closed batch reactor. High yields of Diels-Alder products were obtained without using solvents and catalysts within a short reaction time in most of the reactions. In particular, several reactions of dienophiles with 1,3-butadiene, which is known as a diene with low reactivity because of its gaseous form, also proceeded with high yields of Diels-Alder products in the closed batch reactor under conditions pressured by the reactant vapor. Solvent-free reactions provided high yields compared to reactions in solvent since the reaction heat directly resulted in increasing the reaction temperature and pressure. Energy in the exothermic reaction was used effectively in the closed batch system under solvent-free conditions.
Toluene dioxygenase mediated oxidation of halogen-substituted benzoate esters
Semak, Vladislav,Metcalf, Thomas A.,Endoma-Arias, Mary Ann A.,MacH, Pavel,Hudlicky, Tomas
experimental part, p. 4407 - 4416 (2012/07/14)
A series of ortho-, meta-, and para- halogen-substituted methyl benzoate esters was subjected to enzymatic dihydroxylation via the whole-cell fermentation with E. coli JM109 (pDTG601A). Only ortho-substituted benzoates were metabolized. Methyl 2-fluorobenzoate yielded one diol regioselectively whereas methyl 2-chloro-, methyl 2-bromo- and methyl 2-iodobenzoates each yielded a mixture of regioisomers. Absolute stereochemistry was determined for all new metabolites. Computational analysis of these results and a possible rationale for the regioselectivity of the enzymatic dihydroxylation is advanced.
GLYCOMIMETIC-PEPTIDOMIMETIC INHIBITORS OF E-SELECTINS AND CXCR4 CHEMOKINE RECEPTORS
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Page/Page column 59, (2012/05/20)
Compounds, compositions and methods are provided for treating cancer and inflammatory diseases, and for releasing cells such as stem cells (e.g., bone marrow progenitor cells) into circulating blood and enhancing retention of the cells in the blood. More specifically, glycomimetic-peptidomimetic compounds that inhibit both E-selectins and CXCR4 chemokine receptors are described.
Pre-organization of the core structure of E-selectin antagonists
Schwizer, Daniel,Patton, John T.,Cutting, Brian,Smiesko, Martin,Wagner, Beatrice,Kato, Ako,Weckerle, Celine,Binder, Florian P. C.,Rabbani, Said,Schwardt, Oliver,Magnani, John L.,Ernst, Beat
, p. 1342 - 1351 (2012/04/04)
A new class of N-acetyl-dglucosamine (GlcNAc) mimics for Eselectin antagonists was designed and synthesized. The mimic consists of a cyclohexane ring substituted with alkyl substituents adjacent to the linking position of the fucose moiety. Incorporation into E-selectin antagonists led to the test compounds 8 and the 2'-benzoylated analogues 21, which exhibit affinities in the low micromolar range. By using saturation transfer difference (STD)-NMR it could be shown that the increase in affinity does not result from an additional hydrophobic contact of the alkyl substituent with the target protein E-selectin, but rather from a steric effect stabilizing the antagonist in its bioactive conformation. The loss of affinity found for antagonists 10 and 35 containing a methyl substituent in a remote position (and therefore unable to support to the stabilization of the core) further supports this hypothesis. Finally, when a GlcNAc mimetic containing two methyl substituents (52 and 53) was used, in which one methyl was positioned adjacent to the fucose linking position and the other was in a remote position, the affinity was regained.
PROCESS FOR PRODUCING OPTICALLY ACTIVE CARBOXYLIC ACID
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, (2011/10/12)
It has been demanded to provide a process for industrially producing an intermediate for a compound that exhibits an inhibitory effect on activated blood coagulation factor X and is useful as a preventive and/or therapeutic agent for thrombotic diseases. The present invention provides a process for producing the (R-α-phenylethylamine salt of (S)-3-cyclohexene-1-carboxylic acid, comprising reacting 3-cyclohexene-1-carboxylic acid and (R)-α-phenylethylamine using a mixed solvent of water and acetone or a mixed solvent of water and ethyl acetate as a solvent.
