- Kinetic Resolution of Nearly Symmetric 3-Cyclohexene-1-carboxylate Esters Using a Bacterial Carboxylesterase Identified by Genome Mining
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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.
- Dou, Zhe,Chen, Xuanzao,Niwayama, Satomi,Xu, Guochao,Ni, Ye
-
supporting information
p. 3043 - 3047
(2021/05/05)
-
- Ruthenium complex immobilized on supported ionic-liquid-phase (SILP) for alkoxycarbonylation of olefins with CO2
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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.
- Xia, Shi-Ping,Ding, Guang-Rong,Zhang, Rui,Han, Li-Jun,Xu, Bao-Hua,Zhang, Suo-Jiang
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p. 3073 - 3080
(2021/05/05)
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- A Selective and Functional Group-Tolerant Ruthenium-Catalyzed Olefin Metathesis/Transfer Hydrogenation Tandem Sequence Using Formic Acid as Hydrogen Source
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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.
- Zieliński, Grzegorz K.,Majtczak, Jaros?awa,Gutowski, Maciej,Grela, Karol
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p. 2542 - 2553
(2018/03/09)
-
- Protection of COOH and OH groups in acid, base and salt free reactions
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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.
- Zhu, Xiaotao,Qian, Bo,Wei, Rongbiao,Huang, Jian-Dong,Bao, Hongli
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supporting information
p. 1444 - 1447
(2018/04/12)
-
- Enantioselective Diels-Alder Reactions of Carboxylic Ester Dienophiles Catalysed by Titanium-Based Chiral Lewis Acid
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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.
- Choughule, Yogesh K.,Patwardhan, Anand V.
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p. 921 - 926
(2016/07/06)
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- Solvent-free Diels-Alder reaction in a closed batch system
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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.
- Sun, Daolai,Sato, Fumiya,Yamada, Yasuhiro,Sato, Satoshi
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p. 276 - 282
(2013/05/08)
-
- Toluene dioxygenase mediated oxidation of halogen-substituted benzoate esters
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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.
- Semak, Vladislav,Metcalf, Thomas A.,Endoma-Arias, Mary Ann A.,MacH, Pavel,Hudlicky, Tomas
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experimental part
p. 4407 - 4416
(2012/07/14)
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- GLYCOMIMETIC-PEPTIDOMIMETIC INHIBITORS OF E-SELECTINS AND CXCR4 CHEMOKINE RECEPTORS
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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.
- -
-
Page/Page column 59
(2012/05/20)
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- Pre-organization of the core structure of E-selectin antagonists
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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.
- 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
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p. 1342 - 1351
(2012/04/04)
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- GLYCOMIMETIC COMPOUNDS AND METHODS TO INHIBIT INFECTION BY HIV
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Compounds, compositions and methods are provided for use to inhibit infection by human immunodeficiency virus (HIV). More specifically, the present invention relates to glycomimetic compounds that inhibit HIV infection, and uses thereof.
- -
-
-
- PROCESS FOR PRODUCING OPTICALLY ACTIVE CARBOXYLIC ACID
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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.
- -
-
Page/Page column 12
(2011/10/12)
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- NITROOXY CYCLOALKANE DERIVATIVES
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A compound having the structure wherein Y is selected from the group consisting of –C(O)OR2, -C(O)NHR8, -C(CH2)1-2OR3, OH, and or a pharmaceutically acceptable salt thereof, and methods of using the compounds for treating hypertension.
- -
-
Page/Page column 32
(2010/06/17)
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- HETEROBIFUNCTIONAL INHIBITORS OF E-SELECTINS AND CXCR4 CHEMOKINE RECEPTORS
-
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, heterobifunctional compounds that inhibit both E-selectins and CXCR4 chemokine receptors are described.
- -
-
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- A stereospecific palladium-catalyzed route to monoalkyl diazenes for mild allylic reduction
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(Chemical Equation Presented) One step beyond: The first single-step stereospecific transition-metal-catalyzed conversion of allylic electrophiles into monoalkyl diazenes is described. This synthesis of allylic monoalkyl diazenes offers a new strategy for asymmetric synthesis by the reduction of optically active substrates or the use of chiral catalyst systems. Sensitive substrates are reduced in a highly selective manner. Ar = 2-NO2C 6H2.
- Movassaghi, Mohammad,Ahmad, Omar K.
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supporting information; experimental part
p. 8909 - 8912
(2009/05/26)
-
- Methods of use of glycomimetics with replacements for hexoses and n-acetyl hexosamines
-
Methods are provided for using a compound to treat, for example, endothelial dysfunction including vascular abnormalities. More specifically, methods are described for using an oligosaccharide compound or glycomimetic compound wherein a cyclohexane derivative is incorporated in either.
- -
-
-
- Glycomimetic replacements for hexoses and N-acetyl hexosamines
-
Compounds and methods are provided for obtaining oligosaccharide mimics. More specifically, compounds and methods are described wherein oligosaccharide mimics are obtained by incorporating or substituting in a cyclohexane derivative.
- -
-
Page/Page column 18; title page
(2008/12/06)
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- Asymmetric total synthesis of sperabillins B and D via lithium amide conjugate addition
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Diastereoselective conjugate addition of homochiral lithium (R)-N-allyl-N-α-methylbenzylamide to methyl (2E,5E)-hepatadienoate, followed by protecting group manipulation and subsequent iodocyclocarbamation allows a concise route to the core fragment, methyl (3R,5R,6R)-3,6-diamino-5- hydroxyheptanoate, of sperabillins B and D. Differentiation between the C-3 and C-6 primary amino groups of this core amino acid was readily achieved by treatment with acetone, giving the 5,6-isopropylidene and C-3-imine protected diamine, with subsequent regioselective acylation of the C-6-nitrogen facilitating the total synthesis of sperabillin D in 10.8% overall yield, and the first asymmetric synthesis of sperabillin B in 5.8% overall yield.
- Davies, Stephen G.,Haggitt, Jane R.,Ichihara, Osamu,Kelly, Richard J.,Leech, Michael A.,Mortimer, Anne J. Price,Roberts, Paul M.,Smith, Andrew D.
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p. 2630 - 2649
(2007/10/03)
-
- Enzyme catalyzed reverse enantiomeric separation of methyl (±)-3-cyclohexene-1-carboxylate
-
We describe the differences of hydrolase-type enzymes pig liver esterase (PLE), horse liver esterase (HLE), and porcine pancreatic lipase (PPL) on the hydrolysis of methyl (±)-3-cyclohexene-1-carboxylate to afford both enantiomers with 89% to the resultant enantiomerically pure (S)-(-)-3- cyclohexene-1-carboxylic acid was transformed into (1S,5S)-(-)-5-(hydroxymethyl) -2-cyclohexen-1-ol via iodolactonization, subsequent elimination of iodine with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and reduction with lithium aluminum hydride (LAH).
- Tanyeli, Cihangir,Turkut, Engin
-
p. 2057 - 2060
(2007/10/03)
-
- Total asymmetric synthesis of sperabillins B and D
-
A consise route to the core fragment of sperabillins B and D, methyl (3R,5R,6R)-3,6-diamino-5-hydroxyheptanoate, has been developed with a subsequent novel protection strategy allowing the total asymmetric synthesis of sperabillins B and D.
- Davies, Stephen G.,Kelly, Richard J.,Mortimer, Anne J. Price
-
p. 2132 - 2133
(2007/10/03)
-
- Nucleo-δ-peptides Derived from Conformationally Constrained Nucleo-δ-amino Acids: Preparation of Monomers
-
Cyclic nucleo-δ-amino-acids that constitute monomers of a conformationally constrained nucleo-δ-peptide base-pairing system have been prepared. Their synthesis starts with an enantioselectively analyzed chirogenic Diels-Alder reaction, proceeds via a regioselective ε-iodolactamisation process, and ends with a regio- as well as stereoselective introduction of nucleobases through SN2-type opening of a transiently formed N-acylaziridine ring. Extensive use of X-ray crystal-structure analysis has been made to support structure assignments.
- Karig, Gunter,Fuchs, Andreas,Buesing, Arne,Brandstetter, Tilmann,Scherer, Stefan,Rats, Jan W.,Eschenmoser, Albert,Quinkert, Gerhard
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p. 1049 - 1078
(2007/10/03)
-
- Construction of bicyclo[2.2.2]octane ring system via homoallyl-homoallyl radical rearrangement
-
We designed a sequential three-step, one-pot reaction (homoallyl- homoallyl radical rearrangement reaction) to generate highly functionalized bicyclo[2.2.2]octane ring system, and succeeded in developing a novel synthetic method to bicyclo[2.2.2]octane compounds from simple cyclohexene derivatives.
- Toyota, Masahiro,Yokota, Masahiro,Ihara, Masataka
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p. 1551 - 1554
(2007/10/03)
-
- Diastereoselective Diels-Alder reaction of 2-(α,β-unsaturated)acyl-3- phenyl-1-menthopyrazoles
-
The reaction of 2-(α,β-unsaturated)acyl-3-phenyl-1-menthopyrazoles (9) with dienes gave Diels-Alder adducts in good yield. The addition of MgBr2 · OEt2 or ZnCl2 accelerated these reactions through the formation of chelating bonds such as N ··· Mg ··· O=C or N ··· Zn ··· O=C. The structural fixation by these catalysts also promoted the endo and diastereoselectivities of the Diels-Alder addition on the Re-face of the dienophiles. These results were supported by PM3 calculations, in which the heats of formation of the transition states anticipated the remarkable differences between the Re- and Si-facial attacks of the dienes.
- Kashima, Choji,Fukusaka, Kiyoshi,Takahashi, Katsumi,Yokoyama, Yukihiro
-
p. 1108 - 1114
(2007/10/03)
-
- Unsaturated acid derivatives in Diels-Alder cycloadditions: Effect of the extended or cross conjugation
-
Beahvior of pentadienoic acid derivatives in Diels-Alder cycloadditions has been examined in the light of experimental results and theoretical calculations. The effect of cross conjugation to an electron-releasing group has also been investigated for these systems and for simple acrylic acid derivatives.
- Branchadell,Oliva,Ortuno,Rafel,Ventura
-
p. 9001 - 9012
(2007/10/02)
-
- Asymmetric Diels-Alder Reactions of an Acrylic Acid Derivative Using a Chiral Titanium Catalyst
-
Asymmetric Diels-Alder reactions of an acrylic acid derivative using a catalytic amount of a chiral titanium reagent were performed with several dienes.The titanium catalyst was prepared by the alkoxy exchange between dichlorodiisopropoxytitanium(IV) and a chiral 1,4-diol derived from (2R,3R)-tartrate.By the use of the titanium catalyst, the reaction between 3-acryloyl-1,3-oxazolidin-2-one and dienes proceeded in a toluene-petroleum ether mixture in the presence of Molecular Sieves 4A to afford the Diels-Alder adducts in 72-100percent yields and 88 - >96percent enantioselectivity.This reaction can be applied to a diene containing a hetero atom such as 2-ethylthio-1,3-butadiene, which affords the Diels-Alder adduct in a high optical purity.In this paper are also described the methods for determining the optical purities of the obtained 4-substituted 3-cyclohexenecarboxylic acid derivatives.
- Narasaka, Koichi,Tanaka, Hiroko,Kanai, Fumihiko
-
p. 387 - 391
(2007/10/02)
-
- Photochemical decomposition of t-butylperoxyacetals
-
The decomposition of peroxides in the solid phase by UV radiation was investigated.It was shown that the decomposition of peroxides results in the formation of unstable alkoxy radicals, which decompose at C-C or C-H bonds, giving rise to alkyl radicals.An appreciable similarity between the final products of the decomposition of solid peroxides by UV radiation and the products of the thermolysis of the same peroxides was established, which led to the hypothesis that there is some similarity between the mechanism of the decomposition of the peroxides.
- Turovskii, A. A.,Luk'yanenko, L. V.,Kucher, R. V.,Petrenko, V. V.
-
p. 1157 - 1160
(2007/10/02)
-
- A NEW METHOD FOR THE CONVERSION OF ALDEHYDES TO METHYL ESTERS USING PYRIDINIUM DICHROMATE AND METHANOL IN DIMETHYLFORMAMIDE.
-
A new method for the conversion of aldehydes to methyl esters using pyridinium dichromate and methanol in DMF is described.
- O'Connor, Brian,Just, George
-
p. 3235 - 3236
(2007/10/02)
-
- General Syntheses of 6- and 7-Carbomethoxy-trans-1-heteradecalins and 6- and 7-Carbomethoxy-trans-2-heteradecalins
-
Two routes to all of the title compounds in the oxa and aza series have been studied.The most general path, involving a cyclohexene oxide intermediate, was not successful becauase of difficulty in separating regioisomers.Allylation of 4-carbomethoxycyclohexanone (11) followed by reduction produced the required trans-disubstituted allyl alcohols, which were converted to all of the desired 6-carbomethoxy-trans-1-heteradecalins.The allyl ketones were subjected to a homologation-side chain contraction sequence to produce the 6-carbomethoxy-trans-2-heteradecalins.Allylation of 3-carbomethoxycyclohexanone (12) was not regioselective, but all four product isomers were characterized.The desired 5-carbomethoxy-2-allylcyclohexanone isomers (27 and 28) were converted to the 7-carbomethoxy-trans-decalins by similar series of reactions
- Hirsch, Jerry A.,Truc, Vu Chi
-
p. 2218 - 2227
(2007/10/02)
-
- LACTONE FORMATION USING TMSI
-
Iodotrimethylsilane facilitates the rapid lactonization of alcohol ester 2 under remarkably mild conditions.
- Walley, D.R.,Belletire, J.L.
-
p. 401 - 406
(2007/10/02)
-
- Co-dimerisation of 1,3-Dienes and Acrylic Esters catalysed by Cationic Allylpalladium Complexes: the Role of Phosphines
-
Basic phosphines, especially tributylphosphine, when added in 1:1 ratio to cationic allylpalladium complexes, allow the selective co-dimerisation of 1,3-dienes and acrylic esters to linear, unsaturated esters, presumably owing to the inducement of an η3-η1 shift of the allyl ligands by the phosphines.
- Grenouillet, Pierre,Neibecker, Denis,Tkatchenko, Igor
-
p. 542 - 543
(2007/10/02)
-
- Synthesis and Rearrangement of 1-Substituted Bicyclohexanes
-
Starting from 7-oxobicycloheptane-1-carbonyl chloride (3), bicyclohexane-1-carboxylic acid (9) was prepared via Hunsdiecker degradation and Favorskii rearrangement.The conversion of 9 to 1-methoxybicyclohexane (15) via methyl ketone 12 and acetate 13 was complicated by the facile homoketonization of the elusive bicyclohexane-1-ol (14).Similarly, bicyclohexane-1-amine readily underwent hydrolysis whereas N,N-dimethylbicyclohexane-1-amine (17) proved to be more resistant.Thermolysis of methyl bicyclohexane-1-carboxylate (10) revealed a "normal" rate enhancement (ΔEa ca. 6 kcal/mol = 25 kJ/mol).The effects of 1-acetoxy, 1-methoxy and 1-dimethylamino groups on the rate of rearrangement were unexpectedly small.
- Kirmse, Wolfgang,Sandkuehler, Peter
-
p. 1394 - 1406
(2007/10/02)
-
- The Diels-Alder Route to Allylsilanes from 1-Trimethylsilylbutadienes
-
The synthesis and Diels-Alder reactions of 1-trimethylsilylbutadiene (3) and its 3-methyl (17), 3-trimethylsilyloxy (20), 4-methyl (4), and 4-trimethylsilyl (6) derivatives are reported.The silyl group reduces somewhat the rate of the Diels-Alder reactions, and has, if anything, a small 'ortho'-directing effect on the regioselectivity in the reactions of (3) with methyl acylate, methyl propiolate, citraconic anhydride, and 2,6-dimethylbenzoquinone.The other substituent in the dienes (17), (20), and (4) is therefore the major influence on the regioselectivity in the reactions of these dienes with methyl acrylate and methyl propiolate.The products of the Diels-Alder reactions of (3), (17), and (4) are allylsilanes, which undergo clean protodesilylation with acid, and, with the acid and ester derived from the maleic anhydride adduct of (3), undergo epoxidation and sulphenylation reactions giving an allyl alcohol (33) and an allyl sulphide (37), respectively.The adducts from (20) can be hydrolysed to β-silylketones, which can be converted into enones by bromination. 1-Pentamethyldisilylbutadiene (15) is no more reactive and no more regioselective than (3).The 'ortho'-adduct (42) from the reaction of (3) and methyl propiolate aromatises with DDQ to give methyl m-trimethylsilylbenzoate (53) in high yield, in a reaction involving rearrangement of the silyl group, even though a direct dehydrogenation is an available pathway.
- Carter, Martin J.,Fleming, Ian,Percival, Alan
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p. 2415 - 2434
(2007/10/02)
-
