- Photocatalyzed, β-Selective Hydrocarboxylation of α,β-Unsaturated Esters with CO2under Flow for β-Lactone Synthesis
-
A photocatalyzed, β-selective hydrocarboxylation of α,β-unsaturated esters employing CO2 radical anion generated under flow conditions was developed. A range of substrates bearing a variety of functional groups were tolerated, demonstrating chemoselectivity. A series of quaternary carboxylic acids were obtained from sterically demanding β,β-disubstituted alkenes including those derived from natural products. Mechanistic studies support a Giese-type CO2 radical anion conjugate addition followed by hydrogen atom transfer from (TMS)3SiH as the principal reaction pathway. Finally, a telescoped process involving the described β-carboxylation followed by a α-bromination/β-lactonization sequence provides a strategy for β-lactone synthesis.
- Kang, Guowei,Romo, Daniel
-
p. 1309 - 1315
(2021/02/01)
-
- Synthesis method of trans 1 and 2 - cyclohexane dicarboxylic acid monomethylester
-
The invention provides a synthesis method of trans 1 and 2 - cyclohexane dicarboxylic acid monomethylester, and belongs to the field of organic synthesis. The trans 1-2 -cyclohexane dicarboxylic acid monomethylester synthesis method comprises the following steps: trans-cyclohexane -1 and 2 -dicarboxylic acid anhydride. The methanol and solvent is added to the reaction vessel, stirred and purified to obtain the target product trans 1, 2 - cyclohexanedicarboxylate, wherein the solvent is any one or more of tetrahydrofuran, 2 - methyltetrahydrofuran, benzene, toluene, methylene chloride, chloroform, ethyl acetate, methyl acetate or diethyl ether. Since a specific solvent is selected for the reaction solvent, racemization does not occur in the process of synthesizing trans 1 and 2 - cyclohexane dicarboxylic acid monomethyl ester, and the trans ee and 1 cyclohexane dicarboxylic acid monomethyl ester with higher 2 - value can be finally obtained.
- -
-
Paragraph 0044-0048; 0049-0053
(2021/08/25)
-
- Remote conformational responses to enantiomeric excess in carboxylate-binding dynamic foldamers
-
A crystallographically characterised zinc(ii)-capped foldamer can sense the enantiomeric excess of scalemic carboxylate solutions, including those produced by enantioselective organocatalysis, and can relay this input signal along the foldamer body to a remote glycinamide group, which then provides an NMR spectroscopic output.
- Eccles, Natasha,Le Bailly, Bryden A.F.,Della Sala, Flavio,Vitórica-Yrezábal, I?igo J.,Clayden, Jonathan,Webb, Simon J.
-
supporting information
p. 9331 - 9334
(2019/08/08)
-
- Ionic Liquid Gels: Supramolecular Reaction Media for the Alcoholysis of Anhydrides
-
The search of new enantioselective catalysts, able to promote synthetically useful organic reactions with high levels of asymmetric induction, should be associated with the attention to the suitable reaction medium able to achieve the best efficiency in c
- Rizzo, Carla,Mandoli, Alessandro,Marullo, Salvatore,D'Anna, Francesca
-
p. 6356 - 6365
(2019/05/24)
-
- Synthesis of trans-fused octahydroisoindole-1-carboxylic acids
-
trans-Fused octahydroisoindole-1-carboxylic acids are bicyclic proline analogues of potential interest in the search for new drugs. Within this work, the trans-fused octahydroisoindole system has been constructed using methyl trans-2-(hydroxymethyl)cycloh
- Laborda, Pedro,Sayago, Francisco J.,Cativiela, Carlos,Gotor, Vicente
-
p. 404 - 411
(2018/05/22)
-
- Novel amide-functionalized chloramphenicol base bifunctional organocatalysts for enantioselective alcoholysis of meso-cyclic anhydrides
-
A family of novel chloramphenicol base-amide organocatalysts possessing a NH functionality at C-1 position as monodentate hydrogen bond donor were developed and evaluated for enantioselective organocatalytic alcoholysis of meso-cyclic anhydrides. These structural diversified organocatalysts were found to induce high enantioselectivity in alcoholysis of anhydrides and was successfully applied to the asymmetric synthesis of (S)-GABOB.
- Xu, Lingjun,Han, Shuwen,Yan, Linjie,Wang, Haifeng,Peng, Haihui,Chen, Fener
-
supporting information
p. 309 - 317
(2018/02/19)
-
- Synthesis of cinchona alkaloid sulfonamide polymers as sustainable catalysts for the enantioselective desymmetrization of cyclic anhydrides
-
The Mizoroki-Heck polymerization of cinchona-based sulfonamide dimers and aromatic diiodides was investigated in the presence of a palladium catalyst, to obtain chiral polymers in high yields. An iodobenzenesulfonamide derivative of a cinchona alkaloid was also polymerized via self-polycondensation under the same reaction conditions. The catalytic activities of these chiral polymers were examined by using them as catalysts in the enantioselective desymmetrization of cyclic anhydrides.
- Takata, Shohei,Endo, Yuta,Shahid Ullah, Mohammad,Itsuno, Shinichi
-
p. 72300 - 72305
(2016/08/09)
-
- Development of Bifunctional Thiourea Organocatalysts Derived from a Chloramphenicol Base Scaffold and their Use in the Enantioselective Alcoholysis of meso Cyclic Anhydrides
-
The synthesis of new chloramphenicol-base-derived thiourea organocatalysts, (1S,2R)-12 a–f and (1R,2R)-15 a–c, and their use in the enantioselective alcoholysis of meso-anhydrides are described. In particular, hemiesters afforded excellent enantioselectivities if low loadings of (1S,2R)-12 a–f were used. Almost no enantioselectivities were achieved with the use of (1R,2R)-15 a–c. This technique was used to synthesize (R)-(?)-baclofen.
- Yan, Lin-Jie,Wang, Hai-Feng,Chen, Wen-Xue,Tao, Yuan,Jin, Kai-Jun,Chen, Fen-Er
-
p. 2249 - 2253
(2016/07/19)
-
- Desymmetrization of acid anhydride with asymmetric esterification catalyzed by chiral phosphoric acid
-
Asymmetric desymmetrization of σ-symmetric acid anhydrides was achieved with chiral phosphoric acid as a Br?nsted acid catalyst. The key of success was finding of benzhydrol and 2,2-diphenylethanol as the nucleophiles of choice. The corresponding half esters were obtained in good yields with high selectivity.
- Yamada, Ken-ichi,Oonishi, Akinori,Kuroda, Yusuke,Harada, Shingo,Kiyama, Hiroki,Yamaoka, Yousuke,Takasu, Kiyosei
-
p. 4098 - 4100
(2016/08/18)
-
- Monomeric and Dimeric 9-O Anthraquinone and Phenanthryl Derivatives of Cinchona Alkaloids as Chiral Solvating Agents for the NMR Enantiodiscrimination of Chiral Hemiesters
-
Mono- and bis-alkaloid chiral auxiliaries with anthraquinone or phenanthryl cores were probed as chiral solvating agents (CSAs) for the enantiodiscrimination of chiral cyclic hemiesters. The dimeric anthraquinone derivative and the monomeric phenanthryl o
- Uccello Barretta, Gloria,Mandoli, Alessandro,Balzano, Federica,Aiello, Federica,De Nicola, Beatrice,Del Grande, Alessandro
-
p. 693 - 699
(2015/10/12)
-
- PROCESS OF MAKING PROSTACYCLIN COMPOUNDS WITH LINKER THIOL AND PEGYLATED FORMS
-
A process provides for producing chiral prostacyclin derivatives of Formula (I) in high yield from meso anhydrides.
- -
-
Paragraph 197; 198
(2014/09/30)
-
- Organotextile catalysis
-
Throughout human history, textiles have been integral to daily life, but their exploration in catalysis has been rare. Herein, we show a facile and permanent immobilization of organocatalysts on the textile nylon using ultraviolet light. The catalyst and
- Lee, Ji-Woong,Mayer-Gall, Thomas,Opwis, Klaus,Song, Choong Eui,Gutmann, Jochen Stefan,List, Benjamin
-
p. 1225 - 1229
(2013/09/24)
-
- Synthesis and bifunctional asymmetric organocatalysis of helical poly(phenylacetylene)s bearing cinchona alkaloid pendants via a sulfonamide linkage
-
Four novel helical poly(phenylacetylene)s with amino-functionalized cinchona alkaloid pendant groups connecting to the phenyl rings through a sulfonamide linkage were synthesized by the polymerization of the corresponding phenylacetylene monomers using Rh
- Iida, Hiroki,Tang, Zhenglin,Yashima, Eiji
-
p. 2869 - 2879
(2013/07/27)
-
- A family of novel bifunctional organocatalysts: Highly enantioselective alcoholysis of meso cyclic anhydrides and its application for synthesis of the key intermediate of P2X7 receptor antagonists
-
A family of novel squaramides/sulfamides based on 1,2-alkamine was developed as chiral bifunctional catalysts to promote the asymmetric alcoholysis of meso cyclic anhydrides. The hemiesters were obtained in high yield with up to 93% ee. The usefulness of this methodology was demonstrated in the asymmetric synthesis of the key intermediate of P2X7 receptor antagonists.
- Yang, Hong-Jun,Xiong, Fang-Jun,Li, Jie,Chen, Fen-Er
-
p. 553 - 558
(2013/07/27)
-
- The immobilisation of chiral organocatalysts on magnetic nanoparticles: The support particle cannot always be considered inert
-
A systematic study concerning the immobilisation onto magnetic nanoparticles of three useful classes of chiral organocatalyst which rely on a confluence of weak, easily perturbed van der Waals and hydrogen bonding interactions to promote enantioselective
- Gleeson, Oliver,Davies, Gemma-Louise,Peschiulli, Aldo,Tekoriute, Renata,Gun'Ko, Yurii K.,Connon, Stephen J.
-
scheme or table
p. 7929 - 7940
(2011/12/04)
-
- CINCHONA-BASED BIFUNCTIONAL ORGANOCATALYSTS AND METHOD FOR PREPARING CHIRAL HEMIESTERS USING THE SAME
-
The present invention relates to cinchona-based bifunctional organocatalysts and methods for preparing chiral hemiesters using the same. More specifically, the present invention relates to methods for preparing chiral hemiesters from prochiral or meso cyclic acid anhydrides via desymmetrization, using bifunctional cinchona alkaloid catalysts comprising sulfonamide functional groups.
- -
-
Page/Page column 15
(2011/09/20)
-
- CINCHONA-BASED BIFUCNTIONAL ORGANOCATALYSTS AND METHOD FOR PREPARING CHIRAL HEMIESTERS USING THE SAME
-
The present invention relates to cinchona-based bifunctional organocatalysts and methods for preparing chiral hemiesters using the same. More specifically, the present invention relates to methods for preparing chiral hemiesters from prochiral or meso cyclic acid anhydrides via desymmetrization, using birunctional cinchona alkaloid catalysts comprising sulfonamide functional groups.
- -
-
Page/Page column 33-34; 45
(2010/04/03)
-
- Synthesis of both enantiomers of hemiesters by enantioselective methanolysis of meso cyclic anhydrides catalyzed by α-amino acid-derived chiral thioureas
-
(Figure presented) Both ureas and thioureas derived from l- or d-valine act as bifunctional organocatalysts able to induce the enantioselective alcoholysis of mono-, bi-, and tricyclic meso anhydrides. The desymmetrization occurs in near quantitative yields and excellent enantiomeric ratios (up to >99:1) under low catalyst loading. Both enantiomers of the hemiesters can be directly obtained by changing the configuration of the catalyst.
- Manzano, Ruben,Andres, Jose M.,Muruzabal, Maria-Dolores,Pedrosa, Rafael
-
supporting information; scheme or table
p. 5417 - 5420
(2010/09/07)
-
- A new structural motif for bifunctional bronsted acid/base organocatalysis
-
"Chemical equation presented" Naturally synthetic: Acid/base catalyst (S)-I can be used in highly enantioselective alcoholytic desymmetrizations of meso anhydrides. For example, the methanolysis of cyclobutane anhydride deriva-tive 2 gave hemiester 3 in 99:1 e.r. (see scheme). Ester 3 was used in a short enantioselective synthesis of (+ )-grandisol.
- Wakchaure, Vijay N.,List, Benjamin
-
supporting information; experimental part
p. 4136 - 4139
(2010/08/07)
-
- DOSY NMR for monitoring self aggregation of bifunctional organocatalysts: Increasing enantioselectivity with decreasing catalyst concentration
-
In this report, we demonstrate that self-aggregation is an intrinsic problem of bifunctional organocatalysts, especially in the case when the substrates do not have functional groups which are able to bind strongly with catalyst. Due to their self-associa
- Jang, Hyeong Bin,Rho, Ho Sik,Oh, Joong Suk,Nam, Eun Hye,Park, Sang Eun,Bae, Han Yong,Song, Choong Eui
-
supporting information; experimental part
p. 3918 - 3922
(2010/09/17)
-
- Elucidation of the active conformation of cinchona alkaloid catalyst and chemical mechanism of alcoholysis of meso anhydrides
-
Complementary to enantioselective transformations of planar functionalities, catalytic desymmetrization of meso compounds is another fundamentally important strategy for asymmetric synthesis. However, experimentally established stereochemical models on how a chiral catalyst discriminates between two enantiotopic functional groups in the desymmetrization of a meso substrate are particularly lacking. This article describes our endeavor to elucidate the chemical mechanism and characterization of the active conformation of the cinchona alkaloid-derived catalyst for a desymmetrization of meso cyclic anhydrides via asymmetric alcoholysis. First, our kinetic studies indicate that the cinchona alkaloid-catalyzed alcoholysis proceeds by a general base catalysis mechanism. Furthermore, the active conformer of the cinchona alkaloid-derived catalyst DHQD-PHN was clarified by catalyst conformation studies with a designed, rigid cinchona alkaloid derivative as a probe. These key mechanistic insights enabled us to construct a stereochemical model to rationalize how DHQD-PHN differentiates the two enantiotopic carbonyl groups in the transition state of the asymmetric alcoholysis of meso cyclic anhydrides. This model not only is consistent with the sense of asymmetric induction of the asymmetric alcoholysis but also provides a rationale on how the catalyst tolerates a broad range of cyclic anhydrides. These mechanistic insights further guided us to develop a novel practical catalyst for the enantioselective alcoholysis of meso cyclic anhydrides.
- Li, Hongming,Liu, Xiaofeng,Wu, Fanghui,Tang, Liang,Deng, Li
-
experimental part
p. 20625 - 20629
(2011/10/09)
-
- A polymer-supported Cinchona-based bifunctional sulfonamide catalyst: A highly enantioselective, recyclable heterogeneous organocatalyst
-
The design, synthesis, and catalytic application of a highly enantioselective and indefinitely stable polymer-supported Cinchona-based bifunctional sulfonamide is reported.
- Youk, Sung Hun,Oh, Sang Ho,Rho, Ho Sik,Lee, Je Eun,Lee, Ji Woong,Song, Choong Eui
-
supporting information; scheme or table
p. 2220 - 2222
(2009/09/06)
-
- A novel cost-effective thiourea bifunctional organocatalyst for highly enantioselective alcoholysis of meso-cyclic anhydrides: Enhanced enantioselectivity by configuration inversion
-
A novel inexpensive thiourea bifunctional organocatalyst which can promote the highly enantioselective (up to 95% ee) alcoholysis of mesocyclic anhydrides has been developed. Computational studies on the catalytic process as well as a synthetic application of this new catalyst are also presented.
- Wang, Su-Xi,Chen, Fen-Er
-
supporting information; scheme or table
p. 547 - 552
(2009/10/25)
-
- Highly enantioselective desymmetrization of meso anhydrides by a bifunctional thiourea-based organocatalyst at low catalyst loadings and room temperature
-
(Chemical Equation Presented) Bifunctional (thio)urea-based cinchona alkaloid derivatives have been shown to promote highly efficient enantioselective desymmetrization reactions of meso anhydrides. The most selective of these catalysts is capable of the enantioselective methanolysis of succinic and glutaric anhydride derivatives to form hemiester products with >90% yield and enantiomeric excess at 1 mol % loading and ambient temperature.
- Peschiulli, Aldo,Gun'ko, Yurii,Connon, Stephen J.
-
p. 2454 - 2457
(2008/09/19)
-
- A highly reactive and enantioselective bifunctional organocatalyst for the methanolytic desymmetrization of cyclic anhydrides: Prevention of catalyst aggregation
-
(Chemical Equation Presented) Unprecedented reactivity and high stereoselectivity were observed in the ring opening of meso anhydrides under mild conditions with a cinchona-alkaloid-based sulfonamide catalyst (see scheme). Computation of the catalyst-transition-state analogue (right; gray C, white H, green F, blue N, red O, yellow S) provided insight into the origin of the stereoselectivity.
- Oh, Sang Ho,Rho, Ho Sik,Lee, Ji Woong,Lee, Je Eun,Youk, Sung Hoon,Chin, Jik,Song, Choong Eui
-
supporting information; experimental part
p. 7872 - 7875
(2009/04/10)
-
- Bifunctional organocatalyst for methanolytic desymmetrization of cyclic anhydrides: Increasing enantioselectivity by catalyst dilution
-
Highly enantioselective methanolysis of meso-cyclic anhydride was achieved with bifunctional organocatalyst containing a quinine-thiourea moiety; unusual concentration, temperature and solvent effects on the enantioselectivity can be explained in terms of
- Rho, Ho Sik,Oh, Sang Ho,Lee, Ji Woong,Lee, Jin Yong,Chin, Jik,Song, Choong Eui
-
p. 1208 - 1210
(2008/12/23)
-
- Asymmetric Methanolysis of Cyclic meso-Anhydrides with Tripodal 2,6-trans-1,2,6-Trisubstituted Piperidine as Chiral Amine Catalyst
-
An optically active tripodal amine, (2S,6S)-2,6-bis(o-hydroxyphenyl)-1-(2- pyridylmethyl)piperidine, was proven to be a potent chiral catalyst (1-5 mol%) for methanolytic asymmetric desymmetrization of cyclic meso-anhydrides to hemiesters. A good level of
- Okamatsu, Tohru,Irie, Ryo,Katsuki, Tsutomu
-
p. 1569 - 1572
(2008/02/05)
-
- Heterogeneous organocatalysis for the asymmetric desymmetrization of meso-cyclic anhydrides using silica gel-supported bis-cinchona alkaloids
-
The silica gel-supported bis-cinchona alkaloid 1a was prepared and found to be an efficient heterogeneous chiral organocatalyst with high catalytic activities, enantioselectivities (up to 92% ee), and recyclability for the asymmetric desymmetrization of m
- Kim, Hyun Sook,Song, Yu-Mi,Choi, Jin Seok,Yang, Jung Woon,Han, Hogyu
-
p. 12051 - 12057
(2007/10/03)
-
- Silica gel-supported bis-cinchona alkaloid: A chiral catalyst for the heterogeneous asymmetric desymmetrization of meso-cyclic anhydrides
-
A one-pot conversion of meso-cyclic anhydrides with alcoholysis in diethyl ether using SGS-(DHQ)2AQN 4, a silica gel-supported chiral catalyst, into the corresponding desymmetrized mono ester acids was achieved with enantiomeric excesses of up
- Song, Yu-Mi,Choi, Jin Seok,Yang, Jung Woon,Han, Hogyu
-
p. 3301 - 3304
(2007/10/03)
-
- Application of polymer-supported enzymes and reagents in the synthesis of γ-aminobutyric acid (GABA) analogues
-
Polymer-supported pig liver esterase was used for the resolution of meso-diesters. The enzyme can be recovered quantitatively from the reaction mixture by filtration and reused without significant loss of activity. Further transformation of the resulting enantiomerically enriched carboxylic acids through the application of polymer-supported reagents and scavengers provides a number of GABA-analogues.
- Baxendale, Ian R.,Ernst, Martin,Krahnert, Wolf-Rüdiger,Ley, Steven V.
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p. 1641 - 1644
(2007/10/03)
-
- Enantioselective desymmetrization of meso-cyclic anhydrides catalyzed by hexahydro-1H-pyrrolo[1,2-c]imidazolones
-
Asymmetric methanolysis of meso cyclic carboxylic anhydrides including hexahydrophthalic anhydride proceeded in toluene in the presence of (6R,7aS)-(2-aryl-6-hydroxy)hexahydro-1H-pyrrolo[1,2-c]imidazol-1-one to give the corresponding desymmetrized mono ester acids (e.g. (1S,2R)-2-(methoxycarbonyl)cyclohexane-1-carboxylic acid) with enantiomeric excesses of up to 89%.
- Uozumi, Yasuhiro,Yasoshima, Kayo,Miyachi, Takamasa,Nagai, Shin-ichi
-
p. 411 - 414
(2007/10/03)
-
- Practical and Highly Enantioselective Ring Opening of Cyclic Meso-Anhydrides Mediated by Cinchona Alkaloids
-
The cinchona alkaloid-mediated opening of prochiral cyclic anhydrides in the presence of methanol leading to optically active hemiesters is described. Very structurally diverse anhydrides are converted into their corresponding methyl monoesters, and either enantiomer can be obtained with up to 99% ee by using quinine or quinidine as directing additive. After the reaction, the alkaloids can be recovered almost quantitatively and reused without loss of enantioselectivity. Additionally, a catalytic protocol which permits the substoichiometric use of quinidine in the presence of easily accessible pentamethylpiperidine (pempidine) is presented.
- Bolm, Carsten,Schiffers, Ingo,Dinter, Christian L.,Gerlach, Arne
-
p. 6984 - 6991
(2007/10/03)
-
- Ring opening of cyclic anhydrides: Synthesis of achiral half-esters using Lewis acids
-
A rapid and high yield preparation of half-esters from cyclic anhydrides using alcohols and Lewis acids is described.
- Sabitha, Gowravaram,Srividya,Yadav
-
p. 4015 - 4018
(2007/10/03)
-
- PROCESS FOR PREPARING SYNTHETIC MATRIX METALLOPROTEASE INHIBITORS
-
Synthetic mammalian matrix metalloprotease inhibitors are disclosed that are useful for treating or preventing diseases wherein said diseases are caused by unwanted mammalian matrix metalloprotease activity and include skin disorders, keratoconus, restenosis, rheumatoid arthritis, wounds, cancer, angiogenesis and shock.
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- Cyclic Benzamides as Mixed Dopamine D2/Serotonin 5-HT2 Receptor Antagonists: Potential Atypical Antipsychotic Agents
-
A series of novel 4-(4-(1,2-benzisothiazol-3-yl)-1-piperazinyl)butyl cyclic amides was prepared and evaluated as potential antipsychotic agents. The target compounds were examined in vitro for their binding affinities to the dopamine D2, serotonin 5-HT2,
- Norman, Mark H.,Rigdon, Greg C.,Navas, Frank,Cooper, Barrett R.
-
p. 2552 - 2563
(2007/10/02)
-
- Benzyl Methyl (S)-2-(p-Tolylsulfinyl)maleate, an Efficient Dienophile in Asymmetric Diels-Alder Reactions
-
The enantiomerically pure dienophile 3 was readily prepared in a three-step sequence from benzyl acetate and (-)-(S)-menthyl p-toluenesulfinate (46percent overall yield).This vinyl sulfoxide reacted in high
- Alonso, Ines,Carretero, Juan C.,Ruano, Jose L. Garcia
-
p. 1499 - 1508
(2007/10/02)
-
- Benzyl Methyl (S)-2-(p-Tolylsulfinyl)maleate: An Efficient Dienophile for the Enantioselective Synthesis of Cyclohexadienes
-
The new dienophile, benzyl methyl (S)-2-(p-tolylsulfinyl)maleate, readily prepared in two steps from benzyl acetate, reacts with a wide variety of 1,3-dienes, under catalysis by TiCl4, in a very regioselective and stereoselective manner to give optically
- Alonso, Ines,Carretero, Juan C.,Ruano, Jose L. Garcia
-
p. 3231 - 3232
(2007/10/02)
-
- MATRIX METALLOPROTEASE INHIBITORS
-
Compounds of the formulas STR1 wherein each R 1 is independently H or alkyl (1-8C) and R 2 is alkyl (1-8C) or wherein the proximal R 1 and R 2 taken together are--(CH 2) p--wherein p=3-5;R 3 is H or alkyl (1-4C);R 4 is fused or conjugated unsubstituted or substituted bicycloaryl methylene;n is 0, 1 or 2; m is 0 or 1; andX is OR 5 or NHR 5, wherein R. sup.5 is H or substituted or unsubstituted alkyl (1-12C), aryl (6-12C), aryl alkyl (6-16C); orX is an amino acid residue or amide thereof; orX is the residue of a cyclic amine or heterocyclic amine;wherein R 6 is H or lower alkyl (1-4C) and R 7 is H, lower alkyl (1-4C) or an acyl group, and wherein--CONR 3--is optionally in modified isosteric form are useful for treating conditions which are characterized by unwanted matrix metalloprotease activities.
- -
-
-
- MATRIX METALLOPROTEASE INHIBITORS
-
Compounds of the formulas STR1 wherein each R 1 is independently H or alkyl (1-8C) and R 2 is alkyl (1-8C) or wherein the proximal R 1 and R 2 taken together are--(CH 2) p--wherein p=3-5;R 3 is H or alkyl (1-4C);R. sup.4 is fused or conjugated unsubstituted or substituted bicycloaryl methylene;n is 0, 1 or 2; m is 0 or 1; andx is OR 5 or NHR 5, wherein R. sup.5 is H or substituted or unsubstituted alkyl (1-12C), aryl (6-12C), aryl alkyl (6-16C); orX is an amino acid residue or amide thereof; orX is the residue of a cyclic amine or heterocyclic amine;Y is selected from the group consisting of R 7 ONR 6 CONR 6-, R 6 2 NCONOR 7-, and R 6 CONOR. sup.7-, wherein each R 6 is independently H or lower alkyl (1-4C); R 7 is lower alkyl (1-4C) or an acyl group; andwherein--CONR. sup.3--is optionally in modified isoteric form are inhibitors of matrix metalloproteases.
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-
-
- INHIBITION OF ANGIOGENESIS BY SYNTHETIC MATRIX METALLOPROTEASE INHIBITORS
-
Synthetic mammalian matrix metalloprotease inhibitors are useful in controlling angiogenesis. These compounds are thus useful in controlling the growth of tumors and in controlling neovascular glaucomas.
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-
-
- Stereoselective synthesis of a trans-octahydroindole derivative, precursor of trandolapril (RU 44 570), an inhibitor of angiotensin converting enzyme
-
We describe a stereoselective synthesis of the trans-octahydroindole-2-carboxylic acid 2 a key intermediate in the elaboration of Trandolapril (RU 44 570) 1. The optically active starting material used was obtained by an enzymatic hydrolysis.
- Brion,Marie,Mackiewicz,Roui,Buendia
-
p. 4889 - 4892
(2007/10/02)
-
- Treatment for tissue ulceration
-
Compounds of the formulas STR1 wherein R1 is H and R2 is alkyl (3-8C) or wherein R1 and R2 taken together are --(CH2)n -- wherein n=3-5; R3 is H or alkyl (1-4C); R4 is a substituted or unsubstituted fused or conjugated bicycloaryl methylene; X is OR5 or NHR5, wherein R5 is H or substituted or unsubstituted alkyl (1-12C), aryl (6-12C), aryl alkyl (6-16C); or X is an amino acid residue or amide thereof; or X is the residue of a cyclic amine or heterocyclic amine are useful for treating or preventing ulceration of tissue, especially cornea.
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-
- ENZYMES IN ORGANIC SYNTHESIS. 42. INVESTIGATION OF THE EFFECTS OF THE ISOZYMAL COMPOSITION OF PIG LIVER ESTERASE ON ITS STEREOSELECTIVITY IN PREPARATIVE-SCALE ESTER HYDROLYSES OF ASYMMETRIC SYNTHETIC VALUE.
-
The stereospecificities of the isozyme components of commercially available pig liver esterase have been shown to be essentially the same toward representative monocyclic and acyclic diester substrates. This removes previous concerns that the isozymal com
- Lam,Brown,De Jeso,Lym,Toone,Jones
-
p. 4409 - 4411
(2007/10/02)
-
- Enzyme-catalysed Asymmetric Synthesis, IV. - Synthesis of Homochiral Building Blocks for the Enantioselective Total Synthesis of Cyclopentanoids with an Esterase-catalysed Asymmetric Reaction as Key Step
-
An efficient synthesis of the homochiral building blocks 2a and ent-2a based on the "enantiotopos-enzyme concept" for the total synthesis of cyclopentanoids is described.Key steps thereof are the almost quantitative PLE-catalysed asymmetric hydrolysis of the meso-diester 8 to the homochiral hemiester 9, whose absolute configuration was determined by crystal structure analysis of the (-)-ephedrine salt 12, the preparation of optically pure 9 and ent-9 by a racemate resolution of rac-9 using (+)- and (-)-ephedrine, the enantiodivergent synthesis of the lactones 18 and ent-18 from 9, as well as the enantioconvergent synthesis of 18 or ent-18 from 9 and ent-9 by optional chemoselective reduction of the ester and carboxy group, and finally the regioselective Dieckmann cyclisation of the isomeric diesters 23b/24b and ent-23b/ent-24b, respectively, to give the cyclopentanoid target compounds 2a and ent-2a.The structures of 23b, 24b, rac-2b, and rac-29 were determined by INADEQUATE-13C-NMR experiments.Dieckmann cyclisation of the trans-diester rac-31 also leads to rac-2a and rac-26a.
- Gais, Hans-Joachim,Lukas, Karl L.,Ball, Walter A.,Braun, Siegmar,Lindner, Hans J.
-
p. 687 - 716
(2007/10/02)
-
- A Study of Stereoselective Hydrolysis of Symmetrical Diesters with Pig Liver Esterase
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Pig liver esterase (PLE) catalyzed hydrolysis of dimethyl esters of symmetrical dicarboxylic acids, including meso-diacids, cis-1,2-cycloalkanedicarboxylic acids, and diacids with a prochiral center, was studied with 14 substrates.The products of these stereoselective hydrolyses are chiral monoesters of dicarboxylic acids, with an enantiomeric excess (e.e.) from 10percent to 100percent.Some of these optically active monoesters are valuable synthons in natural products synthesis.An additivity pattern of α- and β-substituents with the glutaric esters on the stereoselectivity of enzymatic hydrolysis was observed.Analysis of the experimental results leads to a model of enzyme stereoselectivity of diester hydrolysis in which the substitution pattern at α- and β-C-atoms is found to determine the absolute configuration of the resulting monoester.
- Mohr, Peter,Waespe-Sarcevic, Nada,Tamm, Christoph,Gawronska, Krystyna,Gawronsky, Jacek K.
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p. 2501 - 2511
(2007/10/02)
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- Conformational Equilibrium in 8-Methyl-cis-2-thiahydrindane and 8-Methyl-cis-2-oxahydrindane by 13C NMR Spectroscopy
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The preferred conformation of 8-methyl-cis-thiahydrindane has been both estimated by 13C NMR chemical shifts and determined by low temperature 13C NMR spectroscopy to be the conformer with the methyl group equatorial with respect to the cyclohexane ring.This result is in disagreement with the interpretation of the temperature dependence of the CD spectra of (+) and (-) 8-methyl-cis-2-thiahydrindane, whereby the conformation with the methyl group axial with respect to the cyclohexane ring was claimed to be the preferred conformation.The preferred conformation of the related oxygen heterocycle, 8-methyl-cis-2-oxahydrindane, has been estimated by 13C NMR chemical shifts to be the conformer with the methyl group axial with respect to the cyclohexane ring.Possible reasons for these observations are discussed.
- Willer, Rodney L.
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p. 261 - 265
(2007/10/02)
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