1
|
Devitt AN, Vargas AL, Zhu W, Des Soye BJ, Butun FA, Alt T, Kaley N, Ferreira GM, Moran GR, Kelleher NL, Liu D, Silverman RB. Design, Synthesis, and Mechanistic Studies of ( R)-3-Amino-5,5-difluorocyclohex-1-ene-1-carboxylic Acid as an Inactivator of Human Ornithine Aminotransferase. ACS Chem Biol 2024; 19:1066-1081. [PMID: 38630468 DOI: 10.1021/acschembio.4c00022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Human ornithine aminotransferase (hOAT), a pyridoxal 5'-phosphate (PLP)-dependent enzyme, has been shown to play an essential role in the metabolic reprogramming and progression of hepatocellular carcinoma (HCC). HCC accounts for approximately 75% of primary liver cancers and is within the top three causes of cancer death worldwide. As a result of treatment limitations, the overall 5-year survival rate for all patients with HCC is under 20%. The prevalence of HCC necessitates continued development of novel and effective treatment methods. In recent years, the therapeutic potential of selective inactivation of hOAT has been demonstrated for the treatment of HCC. Inspired by previous increased selectivity for hOAT by the expansion of the cyclopentene ring scaffold to a cyclohexene, we designed, synthesized, and evaluated a series of novel fluorinated cyclohexene analogues and identified (R)-3-amino-5,5-difluorocyclohex-1-ene-1-carboxylic acid as a time-dependent inhibitor of hOAT. Structural and mechanistic studies have elucidated the mechanism of inactivation of hOAT by 5, resulting in a PLP-inactivator adduct tightly bound to the active site of the enzyme. Intact protein mass spectrometry, 19F NMR spectroscopy, transient state kinetic studies, and X-ray crystallography were used to determine the structure of the final adduct and elucidate the mechanisms of inactivation. Interestingly, despite the highly electrophilic intermediate species conferred by fluorine and structural evidence of solvent accessibility in the hOAT active site, Lys292 and water did not participate in nucleophilic addition during the inactivation mechanism of hOAT by 5. Instead, rapid aromatization to yield the final adduct was favored.
Collapse
Affiliation(s)
- Allison N Devitt
- Department of Chemistry, Chemistry of Life Processes Institute, and Center for Developmental Therapeutics, Northwestern University, Evanston, Illinois 60208, United States
| | - Abigail L Vargas
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Wei Zhu
- Department of Chemistry, Chemistry of Life Processes Institute, and Center for Developmental Therapeutics, Northwestern University, Evanston, Illinois 60208, United States
| | - Benjamin James Des Soye
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
| | - Fatma Ayaloglu Butun
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
| | - Tyler Alt
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Nicholas Kaley
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Glaucio M Ferreira
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo 05508-000, SP, Brazil
| | - Graham R Moran
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Neil L Kelleher
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
| | - Dali Liu
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Richard B Silverman
- Department of Chemistry, Chemistry of Life Processes Institute, and Center for Developmental Therapeutics, Northwestern University, Evanston, Illinois 60208, United States
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
- Department of Pharmacology, Northwestern University, Chicago, Illinois 60611, United States
| |
Collapse
|
2
|
Liu Z, Zhao F, Zhao B, Yang J, Ferrara J, Sankaran B, Venkataram Prasad BV, Kundu BB, Phillips GN, Gao Y, Hu L, Zhu T, Gao X. Structural basis of the stereoselective formation of the spirooxindole ring in the biosynthesis of citrinadins. Nat Commun 2021; 12:4158. [PMID: 34230497 PMCID: PMC8260726 DOI: 10.1038/s41467-021-24421-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 06/17/2021] [Indexed: 11/09/2022] Open
Abstract
Prenylated indole alkaloids featuring spirooxindole rings possess a 3R or 3S carbon stereocenter, which determines the bioactivities of these compounds. Despite the stereoselective advantages of spirooxindole biosynthesis compared with those of organic synthesis, the biocatalytic mechanism for controlling the 3R or 3S-spirooxindole formation has been elusive. Here, we report an oxygenase/semipinacolase CtdE that specifies the 3S-spirooxindole construction in the biosynthesis of 21R-citrinadin A. High-resolution X-ray crystal structures of CtdE with the substrate and cofactor, together with site-directed mutagenesis and computational studies, illustrate the catalytic mechanisms for the possible β-face epoxidation followed by a regioselective collapse of the epoxide intermediate, which triggers semipinacol rearrangement to form the 3S-spirooxindole. Comparing CtdE with PhqK, which catalyzes the formation of the 3R-spirooxindole, we reveal an evolutionary branch of CtdE in specific 3S spirocyclization. Our study provides deeper insights into the stereoselective catalytic machinery, which is important for the biocatalysis design to synthesize spirooxindole pharmaceuticals.
Collapse
Affiliation(s)
- Zhiwen Liu
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Fanglong Zhao
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Boyang Zhao
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Jie Yang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | | | - Banumathi Sankaran
- Department of Molecular Biophysics and Integrated Bioimaging, Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - B V Venkataram Prasad
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Biki Bapi Kundu
- PhD Program in Systems, Synthetic, and Physical Biology, Rice University, Houston, TX, USA
| | - George N Phillips
- Department of Biosciences, Rice University, Houston, TX, USA
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Yang Gao
- Department of Biosciences, Rice University, Houston, TX, USA
| | - Liya Hu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Tong Zhu
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China.
| | - Xue Gao
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA.
- Department of Chemistry, Rice University, Houston, TX, USA.
- Department of Bioengineering, Rice University, Houston, TX, USA.
| |
Collapse
|
3
|
Abstract
A photocatalytic system for the dearomative hydroarylation of benzene derivatives has been developed. Using a combination of an organic photoredox catalyst and an amine reductant, this process operates through a reductive radical-polar crossover mechanism where aryl halide reduction triggers a regioselective radical cyclization event, followed by anion formation and quenching to produce a range of complex spirocyclic cyclohexadienes. This light-driven protocol functions at room temperature in a green solvent system (aq. MeCN) without the need for precious metal-based catalysts or reagents or the generation of stoichiometric metal byproducts.
Collapse
Affiliation(s)
- Autumn R Flynn
- Department of Chemistry and Winship Cancer Institute, Emory University, Atlanta, Georgia 30322, United States
| | - Kelly A McDaniel
- Department of Chemistry and Winship Cancer Institute, Emory University, Atlanta, Georgia 30322, United States
| | - Meredith E Hughes
- Department of Chemistry and Winship Cancer Institute, Emory University, Atlanta, Georgia 30322, United States
| | - David B Vogt
- Department of Chemistry and Winship Cancer Institute, Emory University, Atlanta, Georgia 30322, United States
| | - Nathan T Jui
- Department of Chemistry and Winship Cancer Institute, Emory University, Atlanta, Georgia 30322, United States
| |
Collapse
|
4
|
Papadia P, Micoli K, Barbanente A, Ditaranto N, Hoeschele JD, Natile G, Marzano C, Gandin V, Margiotta N. Platinum(IV) Complexes of trans-1,2-diamino-4-cyclohexene: Prodrugs Affording an Oxaliplatin Analogue that Overcomes Cancer Resistance. Int J Mol Sci 2020; 21:E2325. [PMID: 32230896 PMCID: PMC7177638 DOI: 10.3390/ijms21072325] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/25/2020] [Accepted: 03/26/2020] [Indexed: 11/23/2022] Open
Abstract
Six platinum(IV) compounds derived from an oxaliplatin analogue containing the unsaturated cyclic diamine trans-1,2-diamino-4-cyclohexene (DACHEX), in place of the 1,2-diaminocyclohexane, and a range of axial ligands, were synthesized and characterized. The derivatives with at least one axial chlorido ligand demonstrated solvent-assisted photoreduction. The electrochemical redox behavior was investigated by cyclic voltammetry; all compounds showed reduction potentials suitable for activation in vivo. X-ray photoelectron spectroscopy (XPS) data indicated an X-ray-induced surface reduction of the Pt(IV) substrates, which correlates with the reduction potentials measured by cyclic voltammetry. The cytotoxic activity was assessed in vitro on a panel of human cancer cell lines, also including oxaliplatin-resistant cancer cells, and compared with that of the reference compounds cisplatin and oxaliplatin; all IC50 values were remarkably lower than those elicited by cisplatin and somewhat lower than those of oxaliplatin. Compared to the other Pt(IV) compounds of the series, the bis-benzoate derivative was by far (5-8 times) the most cytotoxic showing that low reduction potential and high lipophilicity are essential for good cytotoxicity. Interestingly, all the complexes proved to be more active than cisplatin and oxaliplatin even in three-dimensional spheroids of A431 human cervical cancer cells.
Collapse
Affiliation(s)
- Paride Papadia
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, 73100 Lecce, Italy
| | - Katia Micoli
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - Alessandra Barbanente
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - Nicoletta Ditaranto
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - James D. Hoeschele
- Department of Chemistry, Eastern Michigan University, Ypsilanti, MI 48197, USA
| | - Giovanni Natile
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| | - Cristina Marzano
- Dipartimento di Scienze del Farmaco, Università di Padova, Via Marzolo 5, 35131 Padova, Italy
| | - Valentina Gandin
- Dipartimento di Scienze del Farmaco, Università di Padova, Via Marzolo 5, 35131 Padova, Italy
| | - Nicola Margiotta
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy
| |
Collapse
|
5
|
Alizadeh A, Bagherinejad A, Bayat F, Hosseini SY, Zhu LG. Diastereoselective synthesis of cyclohexadienes via tandem cyclization strategies. Mol Divers 2018; 23:651-656. [PMID: 30519777 DOI: 10.1007/s11030-018-9900-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 11/29/2018] [Indexed: 11/25/2022]
Abstract
A new protocol has been developed for the diastereoselective synthesis of 1,3-cyclohexadienes using vinyl malononitriles, dibenzalacetones and NaH as reagents in THF. This transformation is comprised of interesting steps like Michael addition, cyclization and ring-opening reactions.
Collapse
Affiliation(s)
- Abdolali Alizadeh
- Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
| | - Akram Bagherinejad
- Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran
| | - Fahimeh Bayat
- Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran
| | - Seyed Yasub Hosseini
- Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran
| | - Long-Guan Zhu
- Department of Chemistry, Zhejiang University, Hangzhou, 310027, People's Republic of China
| |
Collapse
|
6
|
Presser A, Lainer G, Kretschmer N, Schuehly W, Saf R, Kaiser M, Kalt MM. Synthesis of Jacaranone-Derived Nitrogenous Cyclohexadienones and Their Antiproliferative and Antiprotozoal Activities. Molecules 2018; 23:molecules23112902. [PMID: 30405045 PMCID: PMC6278284 DOI: 10.3390/molecules23112902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/19/2018] [Accepted: 10/29/2018] [Indexed: 11/16/2022] Open
Abstract
The cytotoxic and antiprotozoal activities of the phytoquinoide, jacaranone, and related compounds have been an ongoing topic in recent drug discovery. Starting from the natural product-derived cyclohexadienone scaffold, a series of nitrogen-containing derivatives were synthesized and subsequently evaluated for their antiproliferative and antiprotozoal activity. Anticancer potency was analyzed using different types of cancer cell lines: MDA-MB-231 breast cancer, CCRF-CEM leukemia, HCT-116 colon cancer, U251 glioblastoma, and, in addition, non-tumorigenic MRC-5 lung fibroblasts. Antiproliferative activities at micromolar concentrations could be shown. Antiprotozoal activity was assessed against Plasmodium falciparum NF54 and Trypanosoma brucei rhodesiense STIB900. For all compounds, selectivity indices (SI) were calculated based on assessed cytotoxicity towards L6 cells. In addition, the structure-activity-relationships and physicochemical parameters of these compounds are discussed.
Collapse
Affiliation(s)
- Armin Presser
- Institute of Pharmaceutical Sciences, Pharmaceutical Chemistry, University of Graz, Schubertstrasse 1, 8010 Graz, Austria.
| | - Gunda Lainer
- Institute of Pharmaceutical Sciences, Pharmaceutical Chemistry, University of Graz, Schubertstrasse 1, 8010 Graz, Austria.
| | - Nadine Kretschmer
- Institute of Pharmaceutical Sciences, Pharmacognosy, University of Graz, Universitaetsplatz 4, 8010 Graz, Austria.
| | - Wolfgang Schuehly
- Institute of Pharmaceutical Sciences, Pharmacognosy, University of Graz, Universitaetsplatz 4, 8010 Graz, Austria.
| | - Robert Saf
- Institute for Chemistry and Technology of Materials (ICTM), Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria.
| | - Marcel Kaiser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland.
- University of Basel, Petersplatz 1, 4003 Basel, Switzerland.
| | - Marc-Manuel Kalt
- Institute of Pharmaceutical Sciences, Pharmaceutical Chemistry, University of Graz, Schubertstrasse 1, 8010 Graz, Austria.
| |
Collapse
|
7
|
Tibhe GD, Macías MA, Schapiro V, Suescun L, Pandolfi E. General Method for the Synthesis of (-)-Conduritol C and Analogs from Chiral Cyclohexadienediol Scaffolds. Molecules 2018; 23:molecules23071653. [PMID: 29986401 PMCID: PMC6100410 DOI: 10.3390/molecules23071653] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 06/29/2018] [Accepted: 07/01/2018] [Indexed: 11/16/2022]
Abstract
An efficient and facile general method for the synthesis of conduritol C analogs, taking advantage of an enantioselective biocatalysis process of monosubstituted benzenes, is described. The absolute stereochemical patterns of the target molecules (−)-conduritol C, (−)-bromo-conduritol C, and (−)-methyl-conduritol C were achieved by means of chemoenzymatic methods. The stereochemistry present at the homochiral cyclohexadiene-cis-1,2-diols derived from the arene biotransformation and the enantioselective ring opening of a non-isolated vinylepoxide derivative permitted the absolute configuration of the carbon bearing the hydroxyl groups at the target molecules to be established. All three conduritols and two intermediates were crystallized, and their structures were confirmed by X-ray diffraction. The three conduritols and intermediates were isostructural. The versatility of our methodology is noteworthy to expand the preparation of conduritol C analogs starting from toluene dioxygenase (TDO) monosubstituted arene substrates.
Collapse
Affiliation(s)
- Gaurao D Tibhe
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Av. Gral. Flores 2124, Universidad de la República, Montevideo CP11800, Uruguay.
| | - Mario A Macías
- Cryssmat-Lab/DETEMA, Facultad de Química, Av. Gral. Flores 2124, Universidad de la República, Montevideo CP11800, Uruguay.
- Department of Chemistry, Universidad de los Andes, Carrera 1 N8 18 A-12, Bogotá 111711, Colombia.
| | - Valeria Schapiro
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Av. Gral. Flores 2124, Universidad de la República, Montevideo CP11800, Uruguay.
| | - Leopoldo Suescun
- Cryssmat-Lab/DETEMA, Facultad de Química, Av. Gral. Flores 2124, Universidad de la República, Montevideo CP11800, Uruguay.
| | - Enrique Pandolfi
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Av. Gral. Flores 2124, Universidad de la República, Montevideo CP11800, Uruguay.
| |
Collapse
|
8
|
Deng L, Jin L, Dong G. Fused-Ring Formation by an Intramolecular "Cut-and-Sew" Reaction between Cyclobutanones and Alkynes. Angew Chem Int Ed Engl 2018; 57:2702-2706. [PMID: 29338109 PMCID: PMC5849476 DOI: 10.1002/anie.201712487] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/03/2017] [Indexed: 11/10/2022]
Abstract
The development of a catalytic intramolecular "cut-and-sew" transformation between cyclobutanones and alkynes to construct cyclohexenone-fused rings is described herein. The challenge arises from the need for selective coupling at the more sterically hindered proximal position, and can be addressed by using an electron-rich, but less bulky, phosphine ligand. The control experiment and 13 C-labelling study suggest that the reaction may start with cleavage of the less hindered distal C-C bond of cyclobutanones, followed by decarbonylation and CO reinsertion to enable Rh insertion at the more hindered proximal position.
Collapse
Affiliation(s)
- Lin Deng
- Department of Chemistry, University of Chicago, Chicago, IL, 60637, USA
| | - Likun Jin
- Department of Chemistry, University of Chicago, Chicago, IL, 60637, USA
- College of Chemical Engineering, Nanjing University of Science & Technology, Nanjing, 210094, P. R. China
| | - Guangbin Dong
- Department of Chemistry, University of Chicago, Chicago, IL, 60637, USA
| |
Collapse
|
9
|
Urosa A, Tobal IE, de la Granja ÁP, Capitán MC, Moro RF, Marcos IS, Garrido NM, Sanz F, Calle E, Díez D. Diastereoselective synthesis of chiral 1,3-cyclohexadienals. PLoS One 2018; 13:e0192113. [PMID: 29438416 PMCID: PMC5810990 DOI: 10.1371/journal.pone.0192113] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 01/18/2018] [Indexed: 11/18/2022] Open
Abstract
A novel approach to the production of chiral 1,3-cyclohexadienals has been developed. The organocatalysed asymmetric reaction of different β-disubstituted-α,β-unsaturated aldehydes with a chiral α,β-unsaturated aldehyde in the presence of a Jørgensen-Hayashi organocatalyst provides easy and stereocontrolled access to the cyclohexadienal backbone. This method allows for the synthesis of potential photoprotective chiral 1,3-cyclohexadienals and extra extended conjugation compounds in a simple manner.
Collapse
Affiliation(s)
- Aitor Urosa
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Salamanca, Salamanca, Spain
| | - Ignacio E. Tobal
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Salamanca, Salamanca, Spain
| | - Ángela P. de la Granja
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Salamanca, Salamanca, Spain
| | - M. Carmen Capitán
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Salamanca, Salamanca, Spain
| | - R. F. Moro
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Salamanca, Salamanca, Spain
| | - Isidro S. Marcos
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Salamanca, Salamanca, Spain
| | - Narciso M. Garrido
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Salamanca, Salamanca, Spain
| | - Francisca Sanz
- Servicio de Difracción de Rayos X, Universidad de Salamanca, Salamanca, Spain
| | - Emilio Calle
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad de Salamanca, Salamanca, Spain
| | - David Díez
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Salamanca, Salamanca, Spain
- * E-mail:
| |
Collapse
|
10
|
Cui L, Guan XQ, Liu ZM, Fan LY, Li Q, Feng Y. A new pre-column derivatization for valienamine and beta-valienamine using o-phthalaldehyde to determine the epimeric purity by HPLC and application of this method to monitor enzymatic catalyzed synthesis of beta-valienamine. J Asian Nat Prod Res 2017; 19:347-357. [PMID: 28367638 DOI: 10.1080/10286020.2017.1292257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/03/2017] [Indexed: 06/07/2023]
Abstract
Valienamine and β-valienamine are representative C7 N aminocyclitols with significant glycosidase inhibition activity that have been developed as important precursors of drugs for diabetes and lysosomal storage diseases, respectively. The quantitative analysis of these chiral compounds is crucial for asymmetric in vitro biosynthetic processes for converting valienone into valienamine epimers using aminotransferase. Here, we developed an efficient and sensitive method for separation and quantitative analysis of chiral valienamine using reversed-phase high-performance liquid chromatography (HPLC) through o-phthalaldehyde (OPA) pre-column derivatization of the analytes. The epimers were derivatized by OPA in borate buffer (pH 9.0) at room temperature for 30 s, separated on an Eclipse XDB-C18 (5 μm, 4.6 × 150 mm) column, eluted with 22% acetonitrile at 30 °C for 18 min, and detected by a fluorescence detector using 445 nm emission and 340 nm excitation wavelengths. The average resolution of the epimers is 3.86, and the concentration linearity is in the range of 0.02-20 μg/ml. The method proved to be effective, sensitive, and reliable with good intra- and inter-day precision and accuracy, and successfully evaluated the enantiopreference and catalytic capability of the potential aminotransferases on an unnatural prochiral substrate, facilitating the design of an asymmetric biosynthetic route for optically pure valienamine and β-valienamine.
Collapse
Affiliation(s)
- Li Cui
- a State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences , Shanghai Jiao Tong University , Shanghai 200240 , China
| | - Xiao-Qing Guan
- a State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences , Shanghai Jiao Tong University , Shanghai 200240 , China
| | - Zhang-Min Liu
- a State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences , Shanghai Jiao Tong University , Shanghai 200240 , China
| | - Liu-Yin Fan
- a State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences , Shanghai Jiao Tong University , Shanghai 200240 , China
| | - Qian Li
- b School of Life Science & Technology , China Pharmaceutical University , Nanjing 210009 , China
| | - Yan Feng
- a State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences , Shanghai Jiao Tong University , Shanghai 200240 , China
| |
Collapse
|
11
|
Abstract
We report a Rh-catalyzed enantioselective cycloisomerization of α,ω-heptadienes to afford cyclohexenes bearing quaternary carbon centers. Rhodium(I) and a new SDP ligand promote chemoselective formation of a cyclohex-3-enecarbaldehyde motif that is inaccessible by the Diels-Alder cycloaddition. Various α,α-bisallylaldehydes rearrange to generate six-membered rings by a mechanism triggered by aldehyde C-H bond activation. Mechanistic studies suggest a pathway involving regioselective carbometalation and endocyclic β-hydride elimination.
Collapse
Affiliation(s)
- Jung-Woo Park
- Department of Chemistry, University of California, Irvine , 4403 Natural Sciences 1, Irvine, California 92697, United States
| | - Zhiwei Chen
- Department of Chemistry, University of California, Irvine , 4403 Natural Sciences 1, Irvine, California 92697, United States
| | - Vy M Dong
- Department of Chemistry, University of California, Irvine , 4403 Natural Sciences 1, Irvine, California 92697, United States
| |
Collapse
|
12
|
Lan P, White LE, Taher ES, Guest PE, Banwell MG, Willis AC. Chemoenzymatic Synthesis of (+)-Asperpentyn and the Enantiomer of the Structure Assigned to Aspergillusol A. J Nat Prod 2015; 78:1963-8. [PMID: 26270650 DOI: 10.1021/acs.jnatprod.5b00304] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Total syntheses of (+)-asperpentyn (1) and compound ent-2, the enantiomer of the structure, 2, assigned to the natural product aspergillusol A are reported. Both reaction sequences employ the enzymatically derived and enantiomerically pure cis-1,2-dihydrocatechol 4 as starting material and use Sonogashira cross-coupling chemistry to install the required enyne side-chain. The (1)H and (13)C NMR spectroscopic data derived from compound ent-2 match those reported for aspergillusol A, thus suggesting that the gross structure of this natural product has been assigned correctly, although its absolute stereochemistry remains unclear.
Collapse
Affiliation(s)
- Ping Lan
- Research School of Chemistry, Institute of Advanced Studies, The Australian National University , Canberra, ACT 2601, Australia
| | - Lauren E White
- Research School of Chemistry, Institute of Advanced Studies, The Australian National University , Canberra, ACT 2601, Australia
| | - Ehab S Taher
- Research School of Chemistry, Institute of Advanced Studies, The Australian National University , Canberra, ACT 2601, Australia
| | - Prudence E Guest
- Research School of Chemistry, Institute of Advanced Studies, The Australian National University , Canberra, ACT 2601, Australia
| | - Martin G Banwell
- Research School of Chemistry, Institute of Advanced Studies, The Australian National University , Canberra, ACT 2601, Australia
| | - Anthony C Willis
- Research School of Chemistry, Institute of Advanced Studies, The Australian National University , Canberra, ACT 2601, Australia
| |
Collapse
|
13
|
Gebauer J, Werneburg M, Koch M. Improved synthesis of (+/-)-trichodiene--a volatile marker for trichothecene mycotoxins. Nat Prod Commun 2014; 9:741-744. [PMID: 25115067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
Trichodiene is the first and only volatile intermediate in the biosynthesis of Fusarium mycotoxins and its detection in the gas-phase might therefore be of potential interest as a marker for food safety analysis. We herein present an improved diastereoselective synthesis of trichodiene which can be used as an analytical standard for a headspace gas chromatography / mass spectrometry method to be developed.
Collapse
|
14
|
Chae SW, Han AR, Park JH, Rhie JY, Lim HJ, Seo EK, Lee HJ. In vitro and in vivo evaluation of phenylbutenoid dimers as inhibitors of P-glycoprotein. J Nat Prod 2013; 76:2277-2281. [PMID: 24266329 DOI: 10.1021/np4004917] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The expression of P-glycoprotein (P-gp), an ATP-dependent efflux transporter, is closely associated with the failure of chemotherapy and drug absorption. Two synthesized optically active phenylbutenoid dimers, 3S-(3,4-dimethoxyphenyl)-4R-{(E)-3,4-dimethoxystyryl}cyclohex-1-ene (1) and 3R-(3,4-dimethoxyphenyl)-4S-{(E)-3,4-dimethoxystyryl}cyclohex-1-ene (2), were tested for their P-gp inhibitory effects by measuring cellular accumulation and efflux of daunomycin in P-gp-overexpressed human breast cancer cells (MCF-7/ADR). Compound 2 significantly increased the accumulation of daunomycin (539%) and decreased the efflux of this compound (55.4%), and similar results were observed for 1. ATPase assays and Western blot analysis were performed to identify the mechanisms by which compounds 1 and 2 inhibit P-gp. In addition, changes in the pharmacokinetic profile of paclitaxel coadministered with 2 in rats were evaluated. Paclitaxel (25 mg/kg) when orally administered with 2 (5 mg/kg) improved its relative bioavailability by 185%. Compound 2 effectively improved cellular accumulation by reducing the efflux of daunomycin and significantly enhanced oral exposure to paclitaxel. Therefore, compound 2 may be useful for improving oral exposure and cellular availability of drugs that are also substrates of P-gp.
Collapse
Affiliation(s)
- Song Wha Chae
- College of Pharmacy, Graduate School of Pharmaceutical Sciences (Ewha Global Top 5 Program), Ewha Womans University , Seoul 120-750, Korea
| | | | | | | | | | | | | |
Collapse
|
15
|
Abstract
A Rh-catalyzed tandem annulation and (5 + 1) cycloaddition was realized. 3-Hydroxy-1,4-enyne served as the new 5-carbon component for the (5 + 1) cycloaddition. Substituted carbazoles, dibenzofurans, and tricyclic compounds containing a cyclohexadienone moiety could be prepared efficiently. The identification of a byproduct suggests that metal carbene and ketene intermediates may be involved in the (5 + 1) cycloaddition.
Collapse
Affiliation(s)
- Xiaoxun Li
- School of Pharmacy, University of Wisconsin, Madison, 53705, United States
| | - Wangze Song
- School of Pharmacy, University of Wisconsin, Madison, 53705, United States
| | - Weiping Tang
- School of Pharmacy, University of Wisconsin, Madison, 53705, United States
- Department of Chemistry, University of Wisconsin, Madison, 53706, United States
| |
Collapse
|
16
|
Diao T, Pun D, Stahl SS. Aerobic dehydrogenation of cyclohexanone to cyclohexenone catalyzed by Pd(DMSO)2(TFA)2: evidence for ligand-controlled chemoselectivity. J Am Chem Soc 2013; 135:8205-12. [PMID: 23662700 PMCID: PMC3795849 DOI: 10.1021/ja4031648] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The dehydrogenation of cyclohexanones affords cyclohexenones or phenols via removal of 1 or 2 equiv of H2, respectively. We recently reported several Pd(II) catalyst systems that effect aerobic dehydrogenation of cyclohexanones with different product selectivities. Pd(DMSO)2(TFA)2 is unique in its high chemoselectivity for the conversion of cyclohexanones to cyclohexenones, without promoting subsequent dehydrogenation of cyclohexenones to phenols. Kinetic and mechanistic studies of these reactions reveal the key role of the dimethylsulfoxide (DMSO) ligand in controlling this chemoselectivity. DMSO has minimal kinetic influence on the rate of Pd(TFA)2-catalyzed dehydrogenation of cyclohexanone to cyclohexenone, while it strongly inhibits the second dehydrogenation step, conversion of cyclohexenone to phenol. These contrasting kinetic effects of DMSO provide the basis for chemoselective formation of cyclohexenones.
Collapse
Affiliation(s)
- Tianning Diao
- Department of Chemistry, University of Wisconsin - Madison, 1101 University Avenue, Madison, Wisconsin 53706
| | - Doris Pun
- Department of Chemistry, University of Wisconsin - Madison, 1101 University Avenue, Madison, Wisconsin 53706
| | - Shannon S. Stahl
- Department of Chemistry, University of Wisconsin - Madison, 1101 University Avenue, Madison, Wisconsin 53706
| |
Collapse
|
17
|
Zhao Q, Chen D, Li Y, Zhang G, Zhang F, Fan X. Rhodium complex immobilized on graphene oxide as an efficient and recyclable catalyst for hydrogenation of cyclohexene. Nanoscale 2013; 5:882-885. [PMID: 23238302 DOI: 10.1039/c2nr33290f] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Rhodium complexes can be homogeneously immobilized on functionalized graphene oxide through coordination interaction. The obtained catalyst can be readily recycled and shows enhanced activity in the catalytic hydrogenation of cyclohexene.
Collapse
Affiliation(s)
- Qingshan Zhao
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China
| | | | | | | | | | | |
Collapse
|
18
|
Rajak H, Singh Thakur B, Singh A, Raghuvanshi K, Sah AK, Veerasamy R, Sharma PC, Singh Pawar R, Kharya MD. Novel limonene and citral based 2,5-disubstituted-1,3,4-oxadiazoles: a natural product coupled approach to semicarbazones for antiepileptic activity. Bioorg Med Chem Lett 2012; 23:864-8. [PMID: 23265873 DOI: 10.1016/j.bmcl.2012.11.051] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 11/02/2012] [Accepted: 11/13/2012] [Indexed: 11/17/2022]
Abstract
Two novel series of N(4)-(5-(2/3/4-substituted-phenyl)-1,3,4-oxadiazol-2-yl)-N(1)-(2-methyl-5-(prop-1-en-2-yl)cyclohex-2-enylidene)semicarbazide and N(4)-(5-(2/3/4-substituted-phenyl)-1,3,4-oxadiazol-2-yl)-N(1)-(3,7-dimethylocta-3,6-dienylidene)-semicarbazide were synthesized to meet structural prerequisite indispensable for anticonvulsant activity. The anticonvulsant activities of the compounds were investigated using maximal electroshock seizure (MES), subcutaneous pentylenetrtrazole (scPTZ) and subcutaneous strychnine (scSTY) models. The rotorod test was conducted to evaluate neurotoxicity. Some of the selected active compounds were subjected to GABA assay to confirm their mode of action. The outcome of the present investigations proved that the four binding sites pharmacophore model is vital for anticonvulsant activity. The efforts were also made to establish structure-activity relationships among test compounds.
Collapse
Affiliation(s)
- Harish Rajak
- Medicinal Chemistry Research Laboratory, SLT Institute of Pharmaceutical Sciences, Guru Ghasidas University, Bilaspur 495 009, CG, India.
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Cheng TJR, Weinheimer S, Tarbet EB, Jan JT, Cheng YSE, Shie JJ, Chen CL, Chen CA, Hsieh WC, Huang PW, Lin WH, Wang SY, Fang JM, Hu OYP, Wong CH. Development of oseltamivir phosphonate congeners as anti-influenza agents. J Med Chem 2012; 55:8657-70. [PMID: 23009169 PMCID: PMC3492761 DOI: 10.1021/jm3008486] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Oseltamivir phosphonic acid (tamiphosphor, 3a), its monoethyl ester (3c), guanidino-tamiphosphor (4a), and its monoethyl ester (4c) are potent inhibitors of influenza neuraminidases. They inhibit the replication of influenza viruses, including the oseltamivir-resistant H275Y strain, at low nanomolar to picomolar levels, and significantly protect mice from infection with lethal doses of influenza viruses when orally administered with 1 mg/kg or higher doses. These compounds are stable in simulated gastric fluid, liver microsomes, and human blood and are largely free from binding to plasma proteins. Pharmacokinetic properties of these inhibitors are thoroughly studied in dogs, rats, and mice. The absolute oral bioavailability of these compounds was lower than 12%. No conversion of monoester 4c to phosphonic acid 4a was observed in rats after intravenous administration, but partial conversion of 4c was observed with oral administration. Advanced formulation may be investigated to develop these new anti-influenza agents for better therapeutic use.
Collapse
MESH Headings
- Acetamides/chemical synthesis
- Acetamides/pharmacokinetics
- Acetamides/pharmacology
- Administration, Oral
- Animals
- Antiviral Agents/chemical synthesis
- Antiviral Agents/pharmacokinetics
- Antiviral Agents/pharmacology
- Biological Availability
- Blood Proteins/metabolism
- Cyclohexenes/chemical synthesis
- Cyclohexenes/pharmacokinetics
- Cyclohexenes/pharmacology
- Cytopathogenic Effect, Viral/drug effects
- Dogs
- Drug Resistance, Viral
- Drug Stability
- Female
- Humans
- Influenza A Virus, H1N1 Subtype/drug effects
- Influenza A Virus, H1N1 Subtype/enzymology
- Influenza A Virus, H1N1 Subtype/genetics
- Influenza A Virus, H5N1 Subtype/drug effects
- Influenza A Virus, H5N1 Subtype/enzymology
- Alphainfluenzavirus/drug effects
- Alphainfluenzavirus/enzymology
- Alphainfluenzavirus/genetics
- Betainfluenzavirus/drug effects
- Betainfluenzavirus/enzymology
- Madin Darby Canine Kidney Cells
- Male
- Mice
- Mice, Inbred BALB C
- Microsomes, Liver/metabolism
- Mutation
- Neuraminidase/antagonists & inhibitors
- Orthomyxoviridae Infections/drug therapy
- Oseltamivir/pharmacology
- Phosphorous Acids
- Protein Binding
- Rats
- Structure-Activity Relationship
Collapse
Affiliation(s)
- Ting-Jen R. Cheng
- The Genomics Research Center, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei 11529, Taiwan
| | - Steven Weinheimer
- TaiMed Biologics, 5251 California Avenue, Suite 230, Irvine, CA 92617, United States
| | - E. Bart Tarbet
- Institute for Antiviral Research, Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, Utah 84322, United States
| | - Jia-Tsrong Jan
- The Genomics Research Center, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei 11529, Taiwan
| | - Yih-Shyun E. Cheng
- The Genomics Research Center, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei 11529, Taiwan
| | - Jiun-Jie Shie
- The Genomics Research Center, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei 11529, Taiwan
| | - Chun-Lin Chen
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan
| | - Chih-An Chen
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan
| | - Wei-Che Hsieh
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan
| | - Pei-Wei Huang
- School of Pharmacy, National Defense Medical Center, No. 161, Sec. 6, Minquan E. Rd., Taipei 114, Taiwan
| | - Wen-Hao Lin
- School of Pharmacy, National Defense Medical Center, No. 161, Sec. 6, Minquan E. Rd., Taipei 114, Taiwan
| | - Shi-Yun Wang
- The Genomics Research Center, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei 11529, Taiwan
| | - Jim-Min Fang
- The Genomics Research Center, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei 11529, Taiwan
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan
| | - Oliver Yoa-Pu Hu
- School of Pharmacy, National Defense Medical Center, No. 161, Sec. 6, Minquan E. Rd., Taipei 114, Taiwan
| | - Chi-Huey Wong
- The Genomics Research Center, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei 11529, Taiwan
| |
Collapse
|
20
|
Odabaşoğlu M, Albayrak C, Koşar B, Büyükgüngör O. Synthesis, spectroscopic characterizations and quantum chemical computational studies of (Z)-4-[(E)-p-tolyldiazenyl]-6-[(2-hydroxyphenylamino)methylene]-2-methoxycyclohexa-2,4-dienone. Spectrochim Acta A Mol Biomol Spectrosc 2012; 92:357-364. [PMID: 22446785 DOI: 10.1016/j.saa.2012.02.101] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/20/2012] [Accepted: 02/23/2012] [Indexed: 05/31/2023]
Abstract
In this study, the molecular structure and spectroscopic properties of title compound were characterized by X-ray diffraction, FT-IR and UV-vis spectroscopies. These properties of title compound were also investigated from calculative point of view. The X-ray diffraction and FT-IR analyses reveal the existence of keto form in the solid state. UV-vis spectra were recorded in different organic solvents. The results show that title compound exists in both keto and enol forms in DMSO, EtOH but it exists in enol form in benzene. In addition, the title compound in DMSO showed new absorption band at 436 nm due to the high ionizing effect of this solvent. The geometry optimization of title compound in gas phase was performed using DFT method with B3LYP applying 6-311G(d,p) basis set. TD-DFT calculations starting from optimized geometry were carried out in gas phase to calculate excitation energies of title compound. The non-linear optical properties were computed with the same level of theory and title compound showed a good second order nonlinear optical property. In addition, thermodynamic properties were obtained in the range of 100-500 K.
Collapse
Affiliation(s)
- Mustafa Odabaşoğlu
- Pamukkale University, Department of Chemical Technology, 20070 Kınıklı-Denizli, Turkey.
| | | | | | | |
Collapse
|
21
|
Abstract
A method for the palladium-catalyzed trifluoromethylation of cyclohexenyl sulfonates has been developed. Various cyclohexenyl triflates and nonaflates underwent trifluoromethylation under mild reaction conditions using a catalyst system composed of Pd(dba)(2) or [(allyl)PdCl](2) and the monodentate biaryl phosphine ligand (t)BuXPhos. The trifluoromethyl anion (CF(3)(-)) or its equivalent for the process was generated in situ from TMSCF(3) in combination with KF or TESCF(3) in combination with RbF.
Collapse
Affiliation(s)
- Eun Jin Cho
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | | |
Collapse
|
22
|
Chu J, Suh DH, Lee G, Han AR, Chae SW, Lee HJ, Seo EK, Lim HJ. Synthesis and biological activity of optically active phenylbutenoid dimers. J Nat Prod 2011; 74:1817-1821. [PMID: 21770432 DOI: 10.1021/np100942e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The total synthesis of optically active phenylbutenoid dimers 1, 3, and ent-3 is described. The key step to access optically active cyclohexene rings was achieved by Diels-Alder reaction of chiral acryloyloxazolinone 9 and phenylbetadiene 10.
Collapse
Affiliation(s)
- Jeonghyun Chu
- Department of Chemistry, Korea University , Anam-dong, Seongbuk-gu, Seoul 136-701, Korea
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Shu D, Li X, Zhang M, Robichaux PJ, Tang W. Synthesis of highly functionalized cyclohexenone rings: rhodium-catalyzed 1,3-acyloxy migration and subsequent [5+1] cycloaddition. Angew Chem Int Ed Engl 2011; 50:1346-9. [PMID: 21290509 PMCID: PMC3131693 DOI: 10.1002/anie.201006881] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Indexed: 11/05/2022]
Affiliation(s)
- Dongxu Shu
- Department of Chemistry, University of Wisconsin Madison, WI 53706-1322 (USA)
| | - Xiaoxun Li
- The School of Pharmacy, University of Wisconsin Madison, WI 53705-2222 (USA)
| | - Min Zhang
- The School of Pharmacy, University of Wisconsin Madison, WI 53705-2222 (USA)
| | | | - Weiping Tang
- The School of Pharmacy, University of Wisconsin Madison, WI 53705-2222 (USA)
| |
Collapse
|
24
|
Pourbafrani M, Forgács G, Horváth IS, Niklasson C, Taherzadeh MJ. Production of biofuels, limonene and pectin from citrus wastes. Bioresour Technol 2010; 101:4246-50. [PMID: 20149643 DOI: 10.1016/j.biortech.2010.01.077] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 01/14/2010] [Accepted: 01/20/2010] [Indexed: 05/19/2023]
Abstract
Production of ethanol, biogas, pectin and limonene from citrus wastes (CWs) by an integrated process was investigated. CWs were hydrolyzed by dilute-acid process in a pilot plant reactor equipped with an explosive drainage. Hydrolysis variables including temperature and residence time were optimized by applying a central composite rotatable experimental design (CCRD). The best sugar yield (0.41g/g of the total dry CWs) was obtained by dilute-acid hydrolysis at 150 degrees C and 6min residence time. At this condition, high solubilization of pectin present in the CWs was obtained, and 77.6% of total pectin content of CWs could be recovered by solvent recovery. Degree of esterification and ash content of produced pectin were 63.7% and 4.23%, respectively. In addition, the limonene of the CWs was effectively removed through flashing of the hydrolyzates into an expansion tank. The sugars present in the hydrolyzates were converted to ethanol using baker's yeast, while an ethanol yield of 0.43g/g of the fermentable sugars was obtained. Then, the stillage and the remaining solid materials of the hydrolyzed CWs were anaerobically digested to obtain biogas. In summary, one ton of CWs with 20% dry weight resulted in 39.64l ethanol, 45m(3) methane, 8.9l limonene, and 38.8kg pectin.
Collapse
Affiliation(s)
- Mohammad Pourbafrani
- Chemical Reaction Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden; School of Engineering, University of Borås, 501 90 Borås, Sweden.
| | | | | | | | | |
Collapse
|
25
|
Abstract
Diels-Alder cycloadditions of highly substituted cyclohexadienes derived from rhodium-mediated [2 + 2 + 2] cyclizations are reported. Reactive heterodienophiles, including singlet oxygen ((1)O(2)), 4-substituted-1,2,4-triazoline-3,5-diones (TADs), and aryl- and acylnitroso compounds were employed, yielding novel heterocyclic products.
Collapse
Affiliation(s)
- Amanda L. Jones
- Department of Chemistry and the Center for Chemical Methodology and Library, Development (CMLD-BU), Boston University, Boston, Massachusetts 02215
| | - John K. Snyder
- Department of Chemistry and the Center for Chemical Methodology and Library, Development (CMLD-BU), Boston University, Boston, Massachusetts 02215
| |
Collapse
|
26
|
Fujioka H, Komatsu H, Nakamura T, Miyoshi A, Hata K, Ganesh J, Murai K, Kita Y. Organic synthesis using a hypervalent iodine reagent: unexpected and novel domino reaction leading to spiro cyclohexadienone lactones. Chem Commun (Camb) 2010; 46:4133-5. [PMID: 20520878 DOI: 10.1039/b925687c] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Hiromichi Fujioka
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Mauleón P, Zeldin RM, González AZ, Toste FD. Ligand-controlled access to [4 + 2] and [4 + 3] cycloadditions in gold-catalyzed reactions of allene-dienes. J Am Chem Soc 2009; 131:6348-9. [PMID: 19378998 PMCID: PMC2711638 DOI: 10.1021/ja901649s] [Citation(s) in RCA: 219] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
By adjustment of the electronic properties of the ancilliary ligands, high selectivity can be achieved for either [4 + 2] or [4 + 3] cycloaddition reactions of allene-dienes catalyzed by gold(I). Triarylphosphitegold(I) complexes are employed as catalysts for a [4 + 2] cycloaddition reaction leading to alkylidenecyclohexenes. Conversely, di-tert-butylbiphenylphosphinegold(I)-catalyzed reactions afford cycloheptadienes via [4 + 3] cycloaddition reactions.
Collapse
Affiliation(s)
- Pablo Mauleón
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Rachel M. Zeldin
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Ana Z. González
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - F. Dean Toste
- Department of Chemistry, University of California, Berkeley, CA 94720
| |
Collapse
|
28
|
Lam YH, Cheong PHY, Blasco Mata JM, Stanway SJ, Gouverneur V, Houk KN. Diels-Alder exo selectivity in terminal-substituted dienes and dienophiles: experimental discoveries and computational explanations. J Am Chem Soc 2009; 131:1947-57. [PMID: 19154113 PMCID: PMC2635921 DOI: 10.1021/ja8079548] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Diels-Alder reactions of a series of silyloxydienes and silylated dienes with acyclic alpha,beta-unsaturated ketones and N-acyloxazolidinones have been investigated. The endo/exo stereochemical outcome is strongly influenced by the substitution pattern of the reactants. High exo selectivity was observed when the termini of the diene and the dienophile involved in the shorter of the forming bonds were both substituted, while the normal endo preference was found otherwise. The exo-selective asymmetric Diels-Alder reactions using Evans' oxazolidinone chiral auxiliary furnished a high level of pi-facial selectivity in the same sense as their well-documented endo-selective counterparts. Computational results for these Diels-Alder reactions were consistent with the experimental endo/exo selectivity in most cases. A twist-asynchronous model accounts for the geometries and energies of the computed transition structures.
Collapse
Affiliation(s)
- Yu-hong Lam
- Chemistry Research Laboratory, University of Oxford, UK
| | | | | | | | | | | |
Collapse
|
29
|
Nicolaou KC, Stepan AF, Lister T, Li A, Montero A, Tria GS, Turner CI, Tang Y, Wang J, Denton RM, Edmonds DJ. Design, synthesis, and biological evaluation of platensimycin analogues with varying degrees of molecular complexity. J Am Chem Soc 2008; 130:13110-9. [PMID: 18771264 PMCID: PMC2669665 DOI: 10.1021/ja8044376] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The molecular design, chemical synthesis, and biological evaluation of two distinct series of platensimycin analogues with varying degrees of complexity are described. The first series of compounds probes the biological importance of the benzoic acid subunit of the molecule, while the second series explores the tetracyclic cage domain. The biological data obtained reveal that, while the substituted benzoic acid domain of platensimycin is a highly conserved structural motif within the active compounds with strict functional group requirements, the cage domain of the molecule can tolerate considerable structural modifications without losing biological action. These findings refine our present understanding of the platensimycin pharmacophore and establish certain structure-activity relationships from which the next generation of designed analogues of this new antibiotic may emerge.
Collapse
Affiliation(s)
- K C Nicolaou
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Liu FW, Di Salvo A, Herdewijn P. Synthesis of 2'-cyclohexenylnucleosides and corresponding CeNA building blocks. Curr Protoc Nucleic Acid Chem 2008; Chapter 1:Unit 1.20. [PMID: 18551425 DOI: 10.1002/0471142700.nc0120s33] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A cyclohexene ring has similar structural properties and conformational behavior to a saturated five-membered furanose ring. In particular, it has good hydrolytic stability. Cyclohexenylnucleosides have been utilized in antiviral drug design, and some nucleosides and oligonucleotides based on the cyclohexene system have been developed. For further investigation of these modified nucleosides and oligonucleotides, synthesis of the chiral cyclohexenylnucleosides in high enantiomeric excess and in bulk quantities is necessary. This unit describes the complete synthesis of four enantiomerically pure 5'-hydroxy-4'-hydroxymethyl-2'-cyclohexenylnucleosides (thymine, cytosine, guanine, and adenine) and the four corresponding N-protected 4'-(monomethoxytrityl)oxymethyl cyclohexenyl nucleic acids (CeNA) building blocks. The chirality of these compounds is 1'S, 4'R, and 5'S.
Collapse
Affiliation(s)
- Feng-Wu Liu
- Laboratory of Medicinal Chemistry, Rega Institute for Medical Research, Leuven, Belgium
| | | | | |
Collapse
|
31
|
Fujioka H, Sawama Y, Kotoku N, Ohnaka T, Okitsu T, Murata N, Kubo O, Li R, Kita Y. Concise Asymmetric Total Synthesis of Scyphostatin, a Potent Inhibitor of Neutral Sphingomyelinase. Chemistry 2007; 13:10225-38. [PMID: 17907134 DOI: 10.1002/chem.200700871] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The concise asymmetric total synthesis of scyphostatin has been achieved by condensation of the optically active cyclohexane unit, prepared from the commercially available 1,4-cyclohexadiene by our own method, and the side chain, prepared by the method developed by Hoye and Tennakoon (T. R. Hoye, M. A. Tennakoon, Org. Lett. 2000, 2, 1481-1483). The modification of the epoxy cyclohexenone unit was achieved in a late stage of the total synthesis, and deprotection of the primary alcohol was conducted in the final step. During the synthesis several key reactions were attained: 1) intramolecular bromoetherification of the cyclohexadiene acetal; 2) stereoselective introduction of the tertiary alcohol, 3) deprotection of the acetal function to the aldehyde by combination with silyl triflate/2,4,6-collidine and the one-pot synthesis of the disilyl aldehyde compounds, with different types of silyl groups, from the dihydroxy acetal compounds; and 4) facile deprotection of the 2,4-dimethoxyphenylmethyl ((2,4)DMPM) protecting group of the primary alcohol.
Collapse
Affiliation(s)
- Hiromichi Fujioka
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, 565-0871, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Affiliation(s)
- Yang S Tran
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA
| | | |
Collapse
|
33
|
Richardson AM, Chen CH, Snider BB. Synthesis of Methyl 1-Hydroxy-6-oxo-2-cyclohexenecarboxylate, a Component of Salicortin and Tremulacin, and the Monomer of Idesolide. J Org Chem 2007; 72:8099-102. [PMID: 17867704 DOI: 10.1021/jo701512w] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have developed a short and practical first synthesis of methyl 1-hydroxy-6-oxo-2-cyclohexenecarboxylate (2), which has been known as a component of salicortin and tremulacin since 1970. Birch reduction of the SEM ether of methyl salicylate followed by oxidation of the intermediate enolate with (-)-camphorsulfonyloxaziridine afforded the SEM enol ether of 2. Hydrolysis of the SEM enol ether afforded 2. We did not observe the dimerization of either racemic or optically enriched 2 to give idesolide (1).
Collapse
Affiliation(s)
- Amie M Richardson
- Department of Chemistry MS 015, Brandeis University, Waltham, Massachusetts 02454-9110, USA
| | | | | |
Collapse
|
34
|
Lim C, Kang JE, Lee JE, Shin S. Gold-Catalyzed Tandem C−C and C−O Bond Formation: A Highly Diastereoselective Formation of Cyclohex-4-ene-1,2-diol Derivatives. Org Lett 2007; 9:3539-42. [PMID: 17665922 DOI: 10.1021/ol071402f] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have reported an efficient gold(I)-catalyzed tandem cyclization of tert-butyl carbonate derivatives of hex-1-en-5-yn-3-ol where nucleophilic participation of the O-Boc group appears to intercept a carbocationic (or cyclopropyl carbene) Au intermediate. This novel protocol leads to densely functionalized cyclohexene-3,4-diol derivatives where 1,2- or 1,2,3-stereocenters are controlled in a highly diastereoselective fashion.
Collapse
Affiliation(s)
- Choongmin Lim
- Department of Chemistry, Hanyang University, Seoul Korea 133-791
| | | | | | | |
Collapse
|
35
|
Min SJ, Jones GO, Houk KN, Danishefsky SJ. Creating Quaternary Centers with High Exo Stereoselectivity Using Activated α-Alkynyl Dienophiles. J Am Chem Soc 2007; 129:10078-9. [PMID: 17655309 DOI: 10.1021/ja073528d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sun-Joon Min
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | | | | | | |
Collapse
|
36
|
Deskus JA, Epperson JR, Sloan CP, Cipollina JA, Dextraze P, Qian-Cutrone J, Gao Q, Ma B, Beno BR, Mattson GK, Molski TF, Krause RG, Taber MT, Lodge NJ, Mattson RJ. Conformationally restricted homotryptamines 3. Indole tetrahydropyridines and cyclohexenylamines as selective serotonin reuptake inhibitors. Bioorg Med Chem Lett 2007; 17:3099-104. [PMID: 17391962 DOI: 10.1016/j.bmcl.2007.03.040] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Revised: 03/13/2007] [Accepted: 03/13/2007] [Indexed: 10/23/2022]
Abstract
A series of indole tetrahydropyridine and indole cyclohexenylamines was prepared, and their binding affinities at the human serotonin transporter (SERT) were determined. In particular, a nitrile substituent at the C5 position of the indole ring gave potent SERT activity. The stereochemistry of the N,N-dimethylamine substituent was determined for the most potent indole cyclohexenylamine, 6a. The enantiomers of 6a were energy minimized and compared to other conformationally restricted SSRIs. Compound 6a was found to give a dose-response similar to the SSRI fluoxetine in microdialysis studies in rats.
Collapse
Affiliation(s)
- Jeffrey A Deskus
- Bristol-Myers Squibb Pharmaceutical Research Institute, 5 Research Parkway, Wallingford, CT 06492-7660, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
McCarroll AJ, Bradshaw TD, Westwell AD, Matthews CS, Stevens MFG. Quinols As Novel Therapeutic Agents. 7. Synthesis of Antitumor 4-[1-(Arylsulfonyl-1H-indol-2-yl)]-4-hydroxycyclohexa-2,5-dien-1-ones by Sonogashira Reactions. J Med Chem 2007; 50:1707-10. [PMID: 17343370 DOI: 10.1021/jm061163m] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interaction of 2-iodoaniline or 5-fluoro-2-iodoaniline with a range of arylsulfonyl chlorides affords sulfonamides that undergo Sonogashira couplings under thermal or microwave conditions with the alkyne 4-ethynyl-4-hydroxycyclohexa-2,5-dien-1-one followed by cyclization to 4-[1-(arylsulfonyl-1H-indol-2-yl)]-4-hydroxycyclo-hexa-2,5-dien-1-ones. This method allows for incorporation of a range of substituents into the arylsulfonyl moiety, and compounds showed selective in vitro inhibition of cancer cell lines of colon and renal origin, a feature of compounds bearing the quinol pharmacophore.
Collapse
Affiliation(s)
- Andrew J McCarroll
- Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, University Park, Nottingham, Nottingham, NG7 2RD, United Kingdom
| | | | | | | | | |
Collapse
|
38
|
Blaskovicova M, Gaplovsky A, Blasko J. Synthesis and photochemistry of 1-iodocyclohexene: influence of ultrasound on ionic vs. radical behaviour. Molecules 2007; 12:188-93. [PMID: 17846569 PMCID: PMC6149510 DOI: 10.3390/12020188] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 01/24/2007] [Accepted: 01/25/2007] [Indexed: 11/16/2022] Open
Abstract
Simultaneous application of UV light and ultrasonic irradiation to a reaction mixture containing 1-iodocyclohexene is reported. The irradiation of 1-iodocyclohexene in methanol was carried out with or without addition of zinc. The effect of ultrasound or mechanical stirring on this solid-liquid system was also compared. The irradiation of 1-iodocyclohexene in methanol in the presence of zinc increases the yield of the nucleophilic trapping product, compared with the yield after irradiation in the absence of zinc. The photodegradation of 1-iodocyclohexene was slightly accelerated after addition of zinc. A rapid formation of radical product was accompanied by substantial decrease of 1-iodocyclohexene after application of ultrasound and irradiation without the zinc. The ultrasound significantly affects the photobehaviour of this reaction, predominantly its radical route. The joint application of ultrasound and zinc contributes positively to the production of radical and ionic products. The sonochemical stirring is more effective than mechanical stirring.
Collapse
Affiliation(s)
- Marika Blaskovicova
- Institute of Chemistry, Faculty of Natural Sciences, Comenius University, Mlynska dolina CH-2, SK-842 15, Bratislava, Slovakia.
| | | | | |
Collapse
|
39
|
Abstract
Two principal subunits of the marine algal toxin (-)-gymnodimine were synthesized. A trisubstituted tetrahydrofuran representing C10-C18 of the toxin was prepared via a highly stereoselective iodine-mediated cyclization of an acyclic alkene bearing a bis-2,6-dichlorobenzyl (DCB) ether. The formation of a cis-2,5-disubstituted tetrahydrofuran in this process conforms to a stereodirecting effect by the DCB group proposed by Bartlett and Rychnovsky. A cyclohexene subunit corresponding to the C1-C8, C19-C24 portion of gymnodimine was synthesized via Diels-Alder cycloaddition of a 1,2,3-trisubstituted diene to a symmetrical dienophile obtained from Meldrum's acid. Differentiation of carbonyl groups in the cycloadduct was made by an intramolecular reaction with a neighboring alcohol to form a gamma-lactone. Linkage of the two subunits at C18-C19 was accomplished by using a B-alkyl Suzuki coupling in which a borane prepared from the pendent alkenyl chain of the cyclohexene domain was reacted with the (E)-iodoalkene attached at C16 of the tetrahydrofuran sector. Subsequent transformations positioned functional groups in the coupled product for a future macrocyclization event that would close the 15-membered ring of gymnodimine.
Collapse
Affiliation(s)
- James D White
- Department of Chemistry, Oregon State University, Corvallis, OR 97331-4003, USA.
| | | | | |
Collapse
|
40
|
Carreño MC, Merino E, Ribagorda M, Somoza A, Urbano A. Enantioselective Synthesis of Natural Polyoxygenated Cyclohexanes and Cyclohexenes from [(p-Tolylsulfinyl)methyl]-p-quinols. Chemistry 2007; 13:1064-77. [PMID: 17171737 DOI: 10.1002/chem.200601330] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Exploitation of the beta-hydroxysulfoxide fragment present in a number of enantiomerically pure (SR)- and (SS)-[(p-tolylsulfinyl)methyl]-p-quinols allowed chemo- and stereocontrolled conjugate additions of different organoaluminium reagents to the cyclohexadienone moiety. The same fragment was also shown to act as an efficient chiral masking carbonyl group, after oxidation to sulfone and retroaddition in basic medium, with elimination of methyl p-tolyl sulfone. Through the use of both transformations as key steps, enantiocontrolled syntheses of different natural products-such as the two enantiomers of dihydroepiepoformin, (-)-gabosine O, (+)-epiepoformin, (-)-theobroxide and (+)-4-epigabosine A (an epimer of the natural product gabosine A)-has been achieved. The presence of the beta-hydroxy sulfone moiety makes the cyclic structures rigid, allowing a number of stereoselective transformations such as carbonyl reductions, enone epoxidations or cis-dihydroxylations, en route to the natural structures. The observed selectivities were dependent on the particular substitution in each substrate, providing evidence of a strong influence of remote groups on the preferred approach of the reactants to the reactive conformations. An advanced precursor of natural (+)-harveynone was also synthesized, but the isolation of the natural product was not possible because of the instability of the corresponding enone, containing a triple bond, under the basic conditions necessary to eliminate the beta-hydroxy sulfone. This demonstrated that the limitations of the use of the beta-hydroxy sulfoxide as a chiral protecting carbonyl group were dependent on the relative stabilities of the final targets in the presence of the required base.
Collapse
Affiliation(s)
- M Carmen Carreño
- Departamento de Química Orgánica (C-I) Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain.
| | | | | | | | | |
Collapse
|
41
|
Abstract
Silacyclic allyl silanes, derived from silene-diene Diels-Alder reactions, combine with acetals in the presence of Lewis acids to afford, following oxidation of the intermediate fluorosilane, either butane-1,4-diols or tetrahydronaphthalenes containing four contiguous chiral centres with moderate to good diastereoselectivity.
Collapse
Affiliation(s)
- Nicholas J Hughes
- Department of Chemistry, University of Durham, Science Laboratories, South Road, Durham DH1 3LE, UK
| | | | | | | | | | | |
Collapse
|
42
|
Abstract
[reaction: see text] The diastereomers of 6-amino-cyclohex-3-ene-1,2-diols 1 (4-deoxy-3-conduramines), key building blocks for the syntheses of a large range of natural products, have been enantioselectively prepared. Diastereoselective dihydroxylation of the compounds provided a new family of aminocyclitols 2 (deoxyinosamines). The key reactions of our syntheses are Sharpless catalytic asymmetric epoxidation, diastereoselective addition of vinylmetal reagents to the aldehydes, and ring-closing metathesis (RCM).
Collapse
Affiliation(s)
- Carlos Alegret
- Unitat de Recerca en Síntesi Asimètrica (URSA-PCB), Institut de Recerca Biomédica (IRB), and Departament de Química Orgànica, Universitat de Barcelona, Parc Científic de Barcelona, Spain
| | | | | |
Collapse
|
43
|
Cong X, Yao ZJ. Ring-Closing Metathesis-Based Synthesis of (3R,4R,5S)-4-Acetylamino-5-amino-3-hydroxy- cyclohex-1-ene-carboxylic Acid Ethyl Ester: A Functionalized Cycloalkene Skeleton of GS4104. J Org Chem 2006; 71:5365-8. [PMID: 16808528 DOI: 10.1021/jo060633h] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
(3R,4R,5S)-4-Acetylamino-5-amino-3-hydroxy-cyclohex-1-ene-carboxylic acid ethyl ester, a functionalized cyclohexene skeleton of GS4104, was diastereoselectively synthesized. A major advantage of this synthesis is the use of readily available L-serine to replace frequently used (-)-shikimic acid or (-)-quinic acid as the starting material. Ring-closing metathesis and diastereoselective Grignard reactions successfully served as the key steps. Absolute configurations of the key intermediates were confirmed by corresponding two-dimensional NMR studies.
Collapse
Affiliation(s)
- Xin Cong
- State Key Laboratory of Bioorganic and Natural Product Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China
| | | |
Collapse
|
44
|
Chaudhury S, Donaldson WA. Nucleophilic Addition to (3-Methylpentadienyl)iron(1+) Cations: Counterion Control of Regioselectivity; Application to the Enantioselective Synthesis of 4,5-Disubstituted Cyclohexenones. J Am Chem Soc 2006; 128:5984-5. [PMID: 16669637 DOI: 10.1021/ja055668y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The regioselectivity of malonate addition to (3-methylpentadienyl)Fe(CO)3+ is controlled by the malonate-counterion association. The Li+ salt of malonate proceeds via C1 nucleophilic attack to afford the 1,3Z-diene complex 4a, while reaction of highly dissociated ion pair (i.e., Na+ or Li+/12-crown-4) salt proceeds at the C2 internal carbon to eventually afford cyclohexenone products 6. Reaction of 1a with the sodium salt of bis(8-phenylmenthyl)malonate proceeds with excellent diastereocontrol to afford a single diastereomeric cyclohexenone.
Collapse
Affiliation(s)
- Subhabrata Chaudhury
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201-1881, USA
| | | |
Collapse
|
45
|
Abstract
The second in a series of two papers, this study examines the origins of diastereoselection in the second ring closure of the highly diastereoselective double Heck cyclization of cyclohexenes 1 and 3 that form contiguous quaternary stereocenters. Seven model substrates were synthesized and cyclized to examine the structural features responsible for imparting diastereoselection in the second intramolecular Heck reaction. These studies demonstrate that stereoselection in the formation of the second spirooxindole ring results from the avoidance of steric interactions in the insertion step with the spirooxindole formed in the first Heck cyclization. An axial substituent (carbonyl or arene) is required at the allylic position for high levels of diastereoselection to be realized.
Collapse
Affiliation(s)
- Larry E Overman
- Department of Chemistry, 516 Rowland Hall, University of California, Irvine, CA 92697-2025, USA.
| | | |
Collapse
|
46
|
4-Vinyl-1-cyclohexene diepoxide. Rep Carcinog 2004; 11:III274-5. [PMID: 21089983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
|