401
|
Abstract
![]()
A redox-economic
method for the direct coupling of olefins that
uses an inexpensive iron catalyst and a silane reducing agent is reported.
Thus, unactivated olefins can be joined directly to electron-deficient
olefins in both intra- and intermolecular settings to generate hindered
bicyclic systems, vicinal quaternary centers, and even cyclopropanes
in good yield. The reaction is not sensitive to oxygen or moisture
and has been performed on gram-scale. Most importantly, it allows
access to many compounds that would be difficult or perhaps impossible
to access using other methods.
Collapse
Affiliation(s)
- Julian C Lo
- Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | | | | |
Collapse
|
402
|
Shen Y, Chen J, Liu M, Ding J, Gao W, Huang X, Wu H. Copper-catalyzed direct C–H arylation of pyridine N-oxides with arylboronic esters: one-pot synthesis of 2-arylpyridines. Chem Commun (Camb) 2014; 50:4292-5. [DOI: 10.1039/c3cc48767a] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Copper-catalyzed direct C–H arylation of pyridine N-oxides with arylboronic esters for the one-pot synthesis of 2-arylpyridines without an additional reductant.
Collapse
Affiliation(s)
- Yan Shen
- College of Chemistry & Materials Engineering
- Wenzhou University
- Wenzhou 325035, P. R. China
| | - Jiuxi Chen
- College of Chemistry & Materials Engineering
- Wenzhou University
- Wenzhou 325035, P. R. China
| | - Miaochang Liu
- College of Chemistry & Materials Engineering
- Wenzhou University
- Wenzhou 325035, P. R. China
| | - Jinchang Ding
- College of Chemistry & Materials Engineering
- Wenzhou University
- Wenzhou 325035, P. R. China
| | - Wenxia Gao
- College of Chemistry & Materials Engineering
- Wenzhou University
- Wenzhou 325035, P. R. China
| | - Xiaobo Huang
- College of Chemistry & Materials Engineering
- Wenzhou University
- Wenzhou 325035, P. R. China
| | - Huayue Wu
- College of Chemistry & Materials Engineering
- Wenzhou University
- Wenzhou 325035, P. R. China
| |
Collapse
|
403
|
Prier CK, MacMillan DWC. Amine α-heteroarylation via photoredox catalysis: a homolytic aromatic substitution pathway. Chem Sci 2014; 5:4173-4178. [PMID: 26236461 DOI: 10.1039/c4sc02155j] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The direct α-heteroarylation of tertiary amines has been accomplished via photoredox catalysis to generate valuable benzylic amine pharmacophores. A variety of five-and six-membered chloroheteroarenes are shown to function as viable coupling partners for the α-arylation of a diverse range of cyclic and acyclic amines. Evidence is provided for a homolytic aromatic substitution mechanism, in which a catalyticallygenerated α-amino radical undergoes direct addition to an electrophilic chloroarene.
Collapse
Affiliation(s)
- Christopher K Prier
- Merck Center for Catalysis at Princeton University, Princeton, New Jersey, 08544, USA
| | - David W C MacMillan
- Merck Center for Catalysis at Princeton University, Princeton, New Jersey, 08544, USA
| |
Collapse
|
404
|
Wang R, Falck JR. Room temperature, open-flask C–H arylation of electron-deficient heteroarenes with triazenes: rapid synthesis of heterobiaryls. Org Chem Front 2014. [DOI: 10.1039/c4qo00213j] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aryl triazenes were coupled with heteroarenes via C–H functionalization to produce heterobiaryls in moderate to good yields at ambient temperature.
Collapse
Affiliation(s)
- Rui Wang
- Division of Chemistry
- Department of Biochemistry
- University of Texas Southwestern Medical Center
- Dallas, 75390-9038 USA
| | - John R. Falck
- Division of Chemistry
- Department of Biochemistry
- University of Texas Southwestern Medical Center
- Dallas, 75390-9038 USA
| |
Collapse
|
405
|
Bolli MH, Abele S, Birker M, Bravo R, Bur D, de Kanter R, Kohl C, Grimont J, Hess P, Lescop C, Mathys B, Müller C, Nayler O, Rey M, Scherz M, Schmidt G, Seifert J, Steiner B, Velker J, Weller T. Novel S1P(1) receptor agonists--part 3: from thiophenes to pyridines. J Med Chem 2013; 57:110-30. [PMID: 24367923 DOI: 10.1021/jm4014696] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In preceding communications we summarized our medicinal chemistry efforts leading to the identification of potent, selective, and orally active S1P1 agonists such as the thiophene derivative 1. As a continuation of these efforts, we replaced the thiophene in 1 by a 2-, 3-, or 4-pyridine and obtained less lipophilic, potent, and selective S1P1 agonists (e.g., 2) efficiently reducing blood lymphocyte count in the rat. Structural features influencing the compounds' receptor affinity profile and pharmacokinetics are discussed. In addition, the ability to penetrate brain tissue has been studied for several compounds. As a typical example for these pyridine based S1P1 agonists, compound 53 showed EC50 values of 0.6 and 352 nM for the S1P1 and S1P3 receptor, respectively, displayed favorable PK properties, and penetrated well into brain tissue. In the rat, compound 53 maximally reduced the blood lymphocyte count for at least 24 h after oral dosing of 3 mg/kg.
Collapse
Affiliation(s)
- Martin H Bolli
- Drug Discovery Chemistry, Actelion Pharmaceuticals Ltd. , Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
406
|
Xia R, Xie MS, Niu HY, Qu GR, Guo HM. Radical Route for the Alkylation of Purine Nucleosides at C6 via Minisci Reaction. Org Lett 2013; 16:444-7. [DOI: 10.1021/ol4033336] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ran Xia
- School
of Environment, Henan Normal University, Xinxiang, Henan Province 453007, China
- Collaborative
Innovation Center of Henan Province for Green Manufacturing of Fine
Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry
of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan Province453007, P. R. China
| | - Ming-Sheng Xie
- Collaborative
Innovation Center of Henan Province for Green Manufacturing of Fine
Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry
of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan Province453007, P. R. China
| | - Hong-Ying Niu
- Collaborative
Innovation Center of Henan Province for Green Manufacturing of Fine
Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry
of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan Province453007, P. R. China
| | - Gui-Rong Qu
- School
of Environment, Henan Normal University, Xinxiang, Henan Province 453007, China
- Collaborative
Innovation Center of Henan Province for Green Manufacturing of Fine
Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry
of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan Province453007, P. R. China
| | - Hai-Ming Guo
- School
of Environment, Henan Normal University, Xinxiang, Henan Province 453007, China
- Collaborative
Innovation Center of Henan Province for Green Manufacturing of Fine
Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry
of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan Province453007, P. R. China
| |
Collapse
|
407
|
Inamoto Y, Nishimoto Y, Yasuda M, Baba A. Syntheses of Aldol Products and Cyanohydrins from Carboxylic Acids Using Hydrosilanes, Organosilicon Reagents, and Indium Triiodide Catalyst. CHEM LETT 2013. [DOI: 10.1246/cl.130790] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Yoshihiro Inamoto
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University
| | - Yoshihiro Nishimoto
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University
| | - Makoto Yasuda
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University
| | - Akio Baba
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University
| |
Collapse
|
408
|
Schönherr H, Cernak T. Profound Methyl Effects in Drug Discovery and a Call for New CH Methylation Reactions. Angew Chem Int Ed Engl 2013; 52:12256-67. [DOI: 10.1002/anie.201303207] [Citation(s) in RCA: 569] [Impact Index Per Article: 51.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Indexed: 11/10/2022]
|
409
|
Schönherr H, Cernak T. Ausgeprägte Methyleffekte in der Wirkstoff-Forschung und der Bedarf an neuen C-H-Methylierungsreaktionen. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201303207] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
410
|
Wang H, Guo LN, Duan XH. Silver-Catalyzed Decarboxylative Acylarylation of Acrylamides with α-Oxocarboxylic Acids in Aqueous Media. Adv Synth Catal 2013. [DOI: 10.1002/adsc.201300468] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
411
|
Gansäuer A, Seddiqzai M, Dahmen T, Sure R, Grimme S. Computational study of the rate constants and free energies of intramolecular radical addition to substituted anilines. Beilstein J Org Chem 2013; 9:1620-9. [PMID: 24062821 PMCID: PMC3778327 DOI: 10.3762/bjoc.9.185] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/17/2013] [Indexed: 12/02/2022] Open
Abstract
The intramolecular radical addition to aniline derivatives was investigated by DFT calculations. The computational methods were benchmarked by comparing the calculated values of the rate constant for the 5-exo cyclization of the hexenyl radical with the experimental values. The dispersion-corrected PW6B95-D3 functional provided very good results with deviations for the free activation barrier compared to the experimental values of only about 0.5 kcal mol−1 and was therefore employed in further calculations. Corrections for intramolecular London dispersion and solvation effects in the quantum chemical treatment are essential to obtain consistent and accurate theoretical data. For the investigated radical addition reaction it turned out that the polarity of the molecules is important and that a combination of electrophilic radicals with preferably nucleophilic arenes results in the highest rate constants. This is opposite to the Minisci reaction where the radical acts as nucleophile and the arene as electrophile. The substitution at the N-atom of the aniline is crucial. Methyl substitution leads to slower addition than phenyl substitution. Carbamates as substituents are suitable only when the radical center is not too electrophilic. No correlations between free reaction barriers and energies (ΔG‡ and ΔGR) are found. Addition reactions leading to indanes or dihydrobenzofurans are too slow to be useful synthetically.
Collapse
Affiliation(s)
- Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie der Rheinischen-Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Straße 1, D-53121 Bonn, Germany
| | | | | | | | | |
Collapse
|
412
|
O'Hara F, Blackmond DG, Baran PS. Radical-based regioselective C-H functionalization of electron-deficient heteroarenes: scope, tunability, and predictability. J Am Chem Soc 2013; 135:12122-34. [PMID: 23859263 DOI: 10.1021/ja406223k] [Citation(s) in RCA: 252] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Radical addition processes can be ideally suited for the direct functionalization of heteroaromatic bases, yet these processes are only sparsely used due to the perception of poor or unreliable control of regiochemistry. A systematic investigation of factors affecting the regiochemistry of radical functionalization of heterocycles using alkylsulfinate salts revealed that certain types of substituents exert consistent and additive effects on the regioselectivity of substitution. This allowed us to establish guidelines for predicting regioselectivity on complex π-deficient heteroarenes, including pyridines, pyrimidines, pyridazines, and pyrazines. Since the relative contribution from opposing directing factors was dependent on solvent and pH, it was sometimes possible to tune the regiochemistry to a desired result by modifying reaction conditions. This methodology was applied to the direct, regioselective introduction of isopropyl groups into complex, biologically active molecules, such as diflufenican (44) and nevirapine (45).
Collapse
Affiliation(s)
- Fionn O'Hara
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | | | | |
Collapse
|
413
|
Scales S, Johnson S, Hu Q, Do QQ, Richardson P, Wang F, Braganza J, Ren S, Wan Y, Zheng B, Faizi D, McAlpine I. Studies on the Regioselective Nucleophilic Aromatic Substitution (SNAr) Reaction of 2-Substituted 3,5-Dichloropyrazines. Org Lett 2013; 15:2156-9. [DOI: 10.1021/ol4006695] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stephanie Scales
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - Sarah Johnson
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - Qiyue Hu
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - Quyen-Quyen Do
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - Paul Richardson
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - Fen Wang
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - John Braganza
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - Shijian Ren
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - Yadong Wan
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - Baojiang Zheng
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - Darius Faizi
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| | - Indrawan McAlpine
- La Jolla Laboratories, Pfizer, Inc., 10770 Science Center Drive, San Diego, California 92121, United States, and WuXi App Tec Co., Shanghai, China
| |
Collapse
|
414
|
Suckling CJ. The diversity-oriented synthesis of pteridines - achievements and potential for development. IUBMB Life 2013; 65:283-99. [PMID: 23440881 DOI: 10.1002/iub.1148] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 12/19/2012] [Indexed: 01/10/2023]
Abstract
The importance of pteridines in the key cofactors, tetrahydrofolate and tetrahydrobiopterin, has encouraged the development of the chemistry and chemical biology of pteridines. In order to investigate the latter, versatile synthetic methods are required to prepare designed relatives of the natural cofactors for use as potential drugs or biological probes. Recently, diversity-oriented synthesis has become a particularly powerful and versatile approach to the synthesis of pteridines and related heterocyclic compounds. This article describes and discusses available methods using radical, electrophilic, nucleophilic, and organometal mediated substitution reactions.
Collapse
Affiliation(s)
- Colin J Suckling
- WestCHEM Research School, Department of Pure & Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, Scotland.
| |
Collapse
|
415
|
Andou T, Saga Y, Komai H, Matsunaga S, Kanai M. Cobalt-Catalyzed C4-Selective Direct Alkylation of Pyridines. Angew Chem Int Ed Engl 2013; 52:3213-6. [DOI: 10.1002/anie.201208666] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 12/12/2012] [Indexed: 11/10/2022]
|
416
|
Andou T, Saga Y, Komai H, Matsunaga S, Kanai M. Cobalt-Catalyzed C4-Selective Direct Alkylation of Pyridines. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201208666] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
417
|
Antonchick AP, Burgmann L. Direct Selective Oxidative Cross-Coupling of Simple Alkanes with Heteroarenes. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201209584] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
418
|
Antonchick AP, Burgmann L. Direct Selective Oxidative Cross-Coupling of Simple Alkanes with Heteroarenes. Angew Chem Int Ed Engl 2013; 52:3267-71. [DOI: 10.1002/anie.201209584] [Citation(s) in RCA: 259] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Indexed: 01/19/2023]
|
419
|
Matcha K, Antonchick AP. Metal-free cross-dehydrogenative coupling of heterocycles with aldehydes. Angew Chem Int Ed Engl 2013; 52:2082-6. [PMID: 23307313 DOI: 10.1002/anie.201208851] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Indexed: 12/20/2022]
Affiliation(s)
- Kiran Matcha
- Max-Planck-Institut für Molekulare Physiologie, Abteilung Chemische Biologie, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | | |
Collapse
|
420
|
Matcha K, Antonchick AP. Metal-Free Cross-Dehydrogenative Coupling of Heterocycles with Aldehydes. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201208851] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
421
|
Raffaini G, Melone L, Punta C. Understanding the topography effects on competitive adsorption on a nanosized anatase crystal: a molecular dynamics study. Chem Commun (Camb) 2013; 49:7581-3. [DOI: 10.1039/c3cc43462a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
422
|
|
423
|
Fujiwara Y. My Research Activities in Baran Laboratory: Development of New Reagent/Methodology for Carbon-Hydrogen Bond Functionalization on Heteroaromatic Ring. J SYN ORG CHEM JPN 2013. [DOI: 10.5059/yukigoseikyokaishi.71.953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
424
|
Zaimoku H, Hatta T, Taniguchi T, Ishibashi H. Iodine-Mediated α-Acetoxylation of 2,3-Disubstituted Indoles. Org Lett 2012. [DOI: 10.1021/ol302983t] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Hisaaki Zaimoku
- School of Pharmaceutical Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Takashi Hatta
- School of Pharmaceutical Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Tsuyoshi Taniguchi
- School of Pharmaceutical Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Hiroyuki Ishibashi
- School of Pharmaceutical Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| |
Collapse
|
425
|
Fujiwara Y, Dixon JA, O'Hara F, Funder ED, Dixon DD, Rodriguez RA, Baxter RD, Herlé B, Sach N, Collins MR, Ishihara Y, Baran PS. Practical and innate carbon-hydrogen functionalization of heterocycles. Nature 2012. [PMID: 23201691 PMCID: PMC3518649 DOI: 10.1038/nature11680] [Citation(s) in RCA: 719] [Impact Index Per Article: 59.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Nitrogen-rich heterocyclic compounds have had a profound effect on human health because these chemical motifs are found in a large number of drugs used to combat a broad range of diseases and pathophysiological conditions. Advances in transition-metal-mediated cross-coupling have simplified the synthesis of such molecules; however, C-H functionalization of medicinally important heterocycles that does not rely on pre-functionalized starting materials is an underdeveloped area. Unfortunately, the innate properties of heterocycles that make them so desirable for biological applications--such as aqueous solubility and their ability to act as ligands--render them challenging substrates for direct chemical functionalization. Here we report that zinc sulphinate salts can be used to transfer alkyl radicals to heterocycles, allowing for the mild (moderate temperature, 50 °C or less), direct and operationally simple formation of medicinally relevant C-C bonds while reacting in a complementary fashion to other innate C-H functionalization methods (Minisci, borono-Minisci, electrophilic aromatic substitution, transition-metal-mediated C-H insertion and C-H deprotonation). We prepared a toolkit of these reagents and studied their reactivity across a wide range of heterocycles (natural products, drugs and building blocks) without recourse to protecting-group chemistry. The reagents can even be used in tandem fashion in a single pot in the presence of water and air.
Collapse
Affiliation(s)
- Yuta Fujiwara
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
426
|
Lescot C, Darses B, Collet F, Retailleau P, Dauban P. Intermolecular C-H amination of complex molecules: insights into the factors governing the selectivity. J Org Chem 2012; 77:7232-40. [PMID: 22892031 DOI: 10.1021/jo301563j] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Transition-metal-catalyzed C-H amination via nitrene insertion allows the direct transformation of a C-H into a C-N bond. Given the ubiquity of C-H bonds in organic compounds, such a process raises the problem of regio- and chemoselectivity, a challenging goal even more difficult to tackle as the complexity of the substrate increases. Whereas excellent regiocontrol can be achieved by the use of an appropriate tether securing intramolecular addition of the nitrene, the intermolecular C-H amination remains much less predictable. This study aims at addressing this issue by capitalizing on an efficient stereoselective nitrene transfer involving the combination of a chiral aminating agent 1 with a chiral rhodium catalyst 2. Allylic C-H amination of terpenes and enol ethers occurs with excellent yields as well as with high regio-, chemo-, and diastereoselectivity as a result of the combination of steric and electronic factors. Conjugation of allylic C-H bonds with the π-bond would explain the chemoselectivity observed for cyclic substrates. Alkanes used in stoichiometric amounts are also efficiently functionalized with a net preference for tertiary equatorial C-H bonds. The selectivity, in this case, can be rationalized by steric and hyperconjugative effects. This study, therefore, provides useful information to better predict the site of C-H amination of complex molecules.
Collapse
Affiliation(s)
- Camille Lescot
- Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, UPR 2301 CNRS Avenue de la Terrasse, F-91198 Gif-sur-Yvette, France
| | | | | | | | | |
Collapse
|
427
|
Naturale G, Lamblin M, Commandeur C, Felpin FX, Dessolin J. Direct C-H Alkylation of Naphthoquinones with Amino Acids Through a Revisited Kochi-Anderson Radical Decarboxylation: Trends in Reactivity and Applications. European J Org Chem 2012. [DOI: 10.1002/ejoc.201200722] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
428
|
|
429
|
Studer A. A “Renaissance” in Radical Trifluoromethylation. Angew Chem Int Ed Engl 2012; 51:8950-8. [DOI: 10.1002/anie.201202624] [Citation(s) in RCA: 859] [Impact Index Per Article: 71.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Indexed: 11/09/2022]
|
430
|
Raeder S, Bracher F. A novel approach to the pyridoacridine ring system: synthesis of the topoisomerase inhibitor 13-deazaascididemin. Arch Pharm (Weinheim) 2012; 345:822-6. [PMID: 22760790 DOI: 10.1002/ardp.201200019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Revised: 04/14/2012] [Accepted: 05/11/2012] [Indexed: 11/08/2022]
Abstract
A novel approach to the pyridoacridine ring system of the ascididemin-type marine alkaloids is presented. This approach allows for the introduction of the ring A of the alkaloids by using a simple aromatic aldehyde building block. The viability of this approach is demonstrated with the synthesis of AK37, a bioactive deaza analogue of the alkaloid ascididemin. Starting from 3-cyano-4-methylquinoline, a sequence of regioselective homolytic benzoylation, annulation of a bromopyridine ring, and radical cyclization leads to the pentacyclic ring system.
Collapse
Affiliation(s)
- Stephan Raeder
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians University of Munich, Munich, Germany
| | | |
Collapse
|
431
|
Gansäuer A, Behlendorf M, von Laufenberg D, Fleckhaus A, Kube C, Sadasivam DV, Flowers RA. Katalytische, atomökonomische radikalische Arylierung von Epoxiden. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201200431] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
432
|
Gansäuer A, Behlendorf M, von Laufenberg D, Fleckhaus A, Kube C, Sadasivam DV, Flowers RA. Catalytic, atom-economical radical arylation of epoxides. Angew Chem Int Ed Engl 2012; 51:4739-42. [PMID: 22461392 DOI: 10.1002/anie.201200431] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie der Universität Bonn, Gerhard Domagk Strasse 1, 53121 Bonn, Germany.
| | | | | | | | | | | | | |
Collapse
|
433
|
Fujiwara Y, Dixon JA, Rodriguez RA, Baxter RD, Dixon DD, Collins MR, Blackmond DG, Baran PS. A new reagent for direct difluoromethylation. J Am Chem Soc 2012; 134:1494-7. [PMID: 22229949 DOI: 10.1021/ja211422g] [Citation(s) in RCA: 473] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Molecular scaffolds containing alkylfluorine substituents are desired in many areas of chemical research from materials to pharmaceuticals. Herein, we report the invention of a new reagent (Zn(SO(2)CF(2)H)(2), DFMS) for the innate difluoromethylation of organic substrates via a radical process. This mild, operationally simple, chemoselective, and scalable difluoromethylation method is compatible with a range of nitrogen-containing heteroarene substrates of varying complexity as well as select classes of conjugated π-systems and thiols. Regiochemical comparisons suggest that the CF(2)H radical generated from the new reagent possesses nucleophilic character.
Collapse
Affiliation(s)
- Yuta Fujiwara
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | | | | | | | | | | | | | | |
Collapse
|