1
|
Parvatkar PT, Diagne K, Zhao Y, Manetsch R. Indoloquinoline Alkaloids as Antimalarials: Advances, Challenges, and Opportunities. ChemMedChem 2024:e202400254. [PMID: 38840271 DOI: 10.1002/cmdc.202400254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/30/2024] [Accepted: 06/05/2024] [Indexed: 06/07/2024]
Abstract
Malaria infections affect almost half of the world's population, with over 200 million cases reported annually. Cryptolepis sanguinolenta, a plant native to West Africa, has long been used across various regions of Africa for malaria treatment. Chemical analysis has revealed that the plant is abundant in indoloquinolines, which have been shown to possess antimalarial properties. Cryptolepine, neocryptolepine, and isocryptolepine are well-studied indoloquinoline alkaloids known for their potent antimalarial activity. However, their structural rigidity and associated cellular toxicity are major drawbacks for preclinical development. This review focuses on the potential of indoloquinoline alkaloids (cryptolepine, neocryptolepine, and isocryptolepine) as scaffolds in drug discovery. The article delves into their antimalarial effects in vitro and in vivo, as well as their proposed mechanisms of action and structure-activity relationship studies. Several studies aim to improve these leads by reducing cytotoxicity while preserving or enhancing antimalarial activity and gaining insights into their mechanisms of action. These investigations highlight the potential of indoloquinolines as a scaffold for developing new antimalarial drugs.
Collapse
Affiliation(s)
- Prakash T Parvatkar
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
| | - Khaly Diagne
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
| | - Yingzhao Zhao
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
| | - Roman Manetsch
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
- Center for Drug Discovery, Northeastern University, Boston, MA 02115, USA
- Barnett Institute of Chemical and Biological Analysis, Northeastern University, Boston, MA 02115, USA
| |
Collapse
|
2
|
Håheim KS, Sydnes MO. Regiodivergent Synthesis and Biological Activities of Indoloquinoline Based Compounds. CHEM REC 2024; 24:e202300362. [PMID: 38319822 DOI: 10.1002/tcr.202300362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/15/2024] [Indexed: 02/08/2024]
Abstract
Cryptolepine, neocryptolepine, and isocryptolepine have remained popular synthetic targets ever since their isolation from the aqueous extracts of the West African climbing shrub Cryptolepis sanguinolenta. These natural alkaloids were found to contain significant antimalarial, antiproliferative and antimicrobial activities, making them ideal starting points for the development of novel drug candidates. As natural product synthesis is often plagued with step-heavy procedures and poor atom economy, the discovery of synthetic protocols addressing these concerns are sorely needed. In our laboratories, we have devoted our efforts into the development of regiodivergent synthesis whereby two of the indoloquinoline natural products, namely neocryptolepine and 11H-indolo[3,2-c]quinolines, could be assembled in only a few steps from a common and readily available starting material. Our synthetic endeavors to meet these goals include a cascade palladium-catalyzed Suzuki-Miyuara cross-coupling and intramolecular C-N bond formation and a photochemical nitrene insertion strategy. Furthermore, our methods also allowed for the construction of several diversely functionalized natural product derivatives which were subjected to biological evaluations.
Collapse
Affiliation(s)
- Katja S Håheim
- Department of Chemistry, Bioscience and Environmental Engineering, Faculty of Science and Technology, University of Stavanger, NO.4036, Stavanger, Norway
| | - Magne O Sydnes
- Department of Chemistry, Bioscience and Environmental Engineering, Faculty of Science and Technology, University of Stavanger, NO.4036, Stavanger, Norway
| |
Collapse
|
3
|
Kawahara KP, Ito H, Itami K. Rapid access to polycyclic thiopyrylium compounds from unfunctionalized aromatics by thia-APEX reaction. Chem Commun (Camb) 2023; 59:1157-1160. [PMID: 36594536 DOI: 10.1039/d2cc06706d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We developed a sulfur-embedding annulative π-extension (thia-APEX) reaction that could construct a sulfur-embedding cationic hexagonal aromatic ring, thiopyrylium, onto unfunctionalized aromatics in one step. The key of thia-APEX is the use of S-imidated ortho-arenoyl arenethiols, and a variety of π-extended thiopyryliums can easily be synthesized. The synthesized thiopyryliums showed diverse absorption and emission properties over the visible light to NIR region, depending on minor structural differences.
Collapse
Affiliation(s)
- Kou P Kawahara
- Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.
| | - Hideto Ito
- Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.
| | - Kenichiro Itami
- Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan. .,Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602, Japan
| |
Collapse
|
4
|
Dasi R, Villinger A, Brasholz M. Photocatalytic Azetidine Synthesis by Aerobic Dehydrogenative [2 + 2] Cycloadditions of Amines with Alkenes. Org Lett 2022; 24:8041-8046. [PMID: 36264267 DOI: 10.1021/acs.orglett.2c03291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photocatalytic dehydrogenative [2 + 2] cycloadditions between amines and alkenes were developed that allow for the stereoselective and high-yielding synthesis of functionalized azetidines. The oxidative formal Aza Paternò-Büchi reactions are induced by photoredox-catalyzed aerobic oxidation of dihydroquinoxalinones 1 as the amines, and in the presence of structurally diverse alkenes 3 intermolecular [2 + 2] cyclization to dihydro-1H-azeto[1,2-a]quinoxalin-3(4H)-ones 4 occurs. The utility of the method is illustrated by the selective conversion of amino acid derived dihydroquinoxalinones 1, including oxidation-prone lysine and tryptophan derivatives.
Collapse
Affiliation(s)
- Rajesh Dasi
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Alexander Villinger
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Malte Brasholz
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany.,Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| |
Collapse
|
5
|
Eichhorst A, Gallhof M, Voss A, Sekora A, Eggers L, Le Thi H, Junghanss C, Murua Escobar H, Brasholz M. Spirooxindol‐1,3‐oxazine alkaloids: highly potent and selective antitumor agents evolved from iterative structure optimization. ChemMedChem 2022; 17:e202200162. [PMID: 35491398 PMCID: PMC9400852 DOI: 10.1002/cmdc.202200162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/26/2022] [Indexed: 11/10/2022]
Abstract
Spirooxindole‐1,3‐oxazines are a small and structurally unique class of spirooxindole alkaloids. To date, only four of these compounds have been isolated from natural sources, and their biological properties remained unknown thus far. Dioxyreserpine is a synthetic spirooxindole‐1,3‐oxazine, that can readily be prepared from the Rauvolfia alkaloid (–)‐reserpine by catalytic photooxygenation. While dioxyreserpine itself was now identified as a moderately effective antitumoral agent, structurally modified analogs of it emerged as a new class of highly potent and selective growth inhibitors of various human cancers, including pancreatic cancers. Systematic structural optimization ultimately led to an inhibitor displaying low‐micromolar IC50‐values against six cancer cell lines as well as selective apoptosis induction in vitro.
Collapse
Affiliation(s)
- Annika Eichhorst
- Universitätsklinikum Rostock: Universitatsmedizin Rostock Department of Internal Medicine, Medical Clinic III GERMANY
| | - Malte Gallhof
- Universität Rostock Mathematisch-Naturwissenschaftliche Fakultät: Universitat Rostock Mathematisch-Naturwissenschaftliche Fakultat Institut für Chemie GERMANY
| | - Alice Voss
- Universität Rostock Mathematisch-Naturwissenschaftliche Fakultät: Universitat Rostock Mathematisch-Naturwissenschaftliche Fakultat Institut für Chemie GERMANY
| | - Anett Sekora
- Universitätsklinikum Rostock: Universitatsmedizin Rostock Department of Internal Medicine, Medical Clinic III GERMANY
| | - Leon Eggers
- Universitätsklinikum Rostock: Universitatsmedizin Rostock Department of Internal Medicine, Medical Clinic III GERMANY
| | - Huyen Le Thi
- Hanoi University of Science: Vietnam National University University of Science Institute of Chemistry GERMANY
| | - Christian Junghanss
- Universitätsklinikum Rostock: Universitatsmedizin Rostock Department of Internal Medicine, Medical Clinic III GERMANY
| | - Hugo Murua Escobar
- Universitätsklinikum Rostock: Universitatsmedizin Rostock Department of Internal Medicine, Medical Clinic III GERMANY
| | - Malte Brasholz
- Universitat Rostock Mathematisch-Naturwissenschaftliche Fakultat Institute of Chemistry Albert-Einstein-Str. 3a 18059 Rostock GERMANY
| |
Collapse
|
6
|
de Fátima Â, Fernandes SA, Ferreira de Paiva W, de Freitas Rego Y. The Povarov Reaction: A Versatile Method to Synthesize Tetrahydroquinolines, Quinolines and Julolidines. SYNTHESIS-STUTTGART 2022. [DOI: 10.1055/a-1794-8355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AbstractThe multicomponent Povarov reaction represents a powerful approach for the construction of substances containing N-heterocyclic frameworks. By using the Povarov reaction, in addition to accessing tetrahydroquinolines, quinolines and julolidines in a single step, it is possible to form the following new bonds: two Csp
3–Csp
3 and one Csp
3–Nsp
3, two Csp
2–Csp
2 and one Csp
2–Nsp
2, and four Csp
3–Csp
3 and two Csp
3–Nsp
1, respectively. This short review discusses the main features of the Povarov reaction, including its mechanism, the reaction scope by employing different catalysts and substrates, as well as stereoselective versions.1 Introduction2 Mechanism of the Povarov Reaction3 Tetrahydroquinolines4 Quinolines5 Julolidines6 Concluding Remarks
Collapse
Affiliation(s)
- Ângelo de Fátima
- Departamento de Química, ICEx, Universidade Federal de Minas Gerais
| | | | | | | |
Collapse
|
7
|
Uppalabat T, Tapdara A, Khaikate O, Worakul T, Surawatanawong P, Leowanawat P, Soorukram D, Reutrakul V, Meesin J, Kuhakarn C. Synthesis of indolo- and benzothieno[3,2-c]quinolines via POCl3 mediated tandem cyclization of o-alkynylisocyanobenzenes derived from o-alkynyl-N-phenylformamides. NEW J CHEM 2022. [DOI: 10.1039/d2nj02791g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A synthesis of indolo[3,2-c]quinolines and benzothieno[3,2-c]quinolines has been developed employing o-alkynyl-N-phenylformamide derivatives as the substrates. The reaction proceeded via a tandem process involving POCl3‒assisted intramolecular cyclization of the firstly formed...
Collapse
|
8
|
Ding Y, Kuang J, Xiao X, Wang L, Ma Y. Environmentally Benign Synthesis of Quinoline-Spiroquinazolinones by Iron-Catalyzed Dehydrogenative [4 + 2] Cycloaddition of Secondary/Tertiary Anilines and 4-Methylene-quinazolinones. J Org Chem 2021; 86:12257-12266. [PMID: 34387487 DOI: 10.1021/acs.joc.1c01602] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report an efficient iron-catalyzed cross-dehydrogenative coupling [4 + 2] annulation of secondary/tertiary anilines with quinazolinones to generate quinoline-spiroquinzolinones. The reaction proceeds smoothly with a relatively broad variety of functional groups, a cheap transition metal catalyst (FeCl3), and environmentally friendly oxidant (H2O2/O2) under mild reaction conditions. Creatively, N-methylanilines are employed for the first time for the cycloaddition as both methyl and methylene sources attached to the N atom of tetrahydroquinolines.
Collapse
Affiliation(s)
- Yuxin Ding
- Institute of Advanced Studies and School of Pharmaceutical and Chemical Engineering, Taizhou University, Taizhou 318000, P R China.,School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, P R China
| | - Jinqiang Kuang
- Institute of Advanced Studies and School of Pharmaceutical and Chemical Engineering, Taizhou University, Taizhou 318000, P R China
| | - Xuqiong Xiao
- Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No. 2318 Yuhangtang Road, Hangzhou 311121, P R China
| | - Lei Wang
- Institute of Advanced Studies and School of Pharmaceutical and Chemical Engineering, Taizhou University, Taizhou 318000, P R China
| | - Yongmin Ma
- Institute of Advanced Studies and School of Pharmaceutical and Chemical Engineering, Taizhou University, Taizhou 318000, P R China.,School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, P R China
| |
Collapse
|
9
|
Pokhriyal A, Singh Karki B, Kant R, Rastogi N. Redox-Neutral 1,3-Dipolar Cycloaddition of 2 H-Azirines with 2,4,6-Triarylpyrylium Salts under Visible Light Irradiation. J Org Chem 2021; 86:4661-4670. [PMID: 33677969 DOI: 10.1021/acs.joc.1c00082] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A novel visible light mediated redox-neutral 1,3-dipolar cycloaddition of 2H-azirines with 2,4,6-triarylpyrylium tetrafluoroborate salts providing tetrasubstituted pyrroles has been developed. The 2,4,6-triarylpyrylium salt acts as dipolarophile as well as photosensitizer in the reaction, under blue light irradiation. The control experiments indicated single electron oxidation of 2H-azirines by photoexcited pyrylium salts, followed by coupling between an azaallenyl radical cation and triarylpyranyl radical as the key mechanistic feature. The mild conditions, wide substrate scope, and complete regioselectivity are the noticeable attributes of the reaction.
Collapse
Affiliation(s)
| | - Bhupal Singh Karki
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | | | - Namrata Rastogi
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| |
Collapse
|
10
|
Abstract
Visible light promoted synthetic routes of quinolines using different strategies are hereby documented.
Collapse
Affiliation(s)
- Ajay Kumar Dhiya
- Department of Chemistry
- Indian Institute of Technology Roorkee
- Roorkee-247667
- India
| | - Aparna Monga
- Department of Chemistry
- Indian Institute of Technology Roorkee
- Roorkee-247667
- India
| | - Anuj Sharma
- Department of Chemistry
- Indian Institute of Technology Roorkee
- Roorkee-247667
- India
| |
Collapse
|
11
|
Thobokholt EN, Larghi EL, Bracca ABJ, Kaufman TS. Isolation and synthesis of cryptosanguinolentine (isocryptolepine), a naturally-occurring bioactive indoloquinoline alkaloid. RSC Adv 2020; 10:18978-19002. [PMID: 35518305 PMCID: PMC9054090 DOI: 10.1039/d0ra03096a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 05/04/2020] [Indexed: 11/28/2022] Open
Abstract
Cryptosanguinolentine (isocryptolepine) is one of the minor naturally-occurring monomeric indoloquinoline alkaloids, isolated from the West African climbing shrub Cryptolepis sanguinolenta. The natural product displays such a simple and unique skeleton, which chemists became interested in well before it was found in Nature. Because of its structure and biological activity, the natural product has been targeted for synthesis on numerous occasions, employing a wide range of different strategies. Hence, discussed here are aspects related to the isolation of isocryptolepine, as well as the various approaches toward its total synthesis.
Collapse
Affiliation(s)
- Elida N Thobokholt
- Instituto de Química Rosario (IQUIR, CONICET-UNR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 S2002LRK Rosario Argentina +54-341-4370477 +54-341-4370477
| | - Enrique L Larghi
- Instituto de Química Rosario (IQUIR, CONICET-UNR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 S2002LRK Rosario Argentina +54-341-4370477 +54-341-4370477
| | - Andrea B J Bracca
- Instituto de Química Rosario (IQUIR, CONICET-UNR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 S2002LRK Rosario Argentina +54-341-4370477 +54-341-4370477
| | - Teodoro S Kaufman
- Instituto de Química Rosario (IQUIR, CONICET-UNR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 S2002LRK Rosario Argentina +54-341-4370477 +54-341-4370477
| |
Collapse
|
12
|
Kawahara KP, Matsuoka W, Ito H, Itami K. Synthesis of Nitrogen-Containing Polyaromatics by Aza-Annulative π-Extension of Unfunctionalized Aromatics. Angew Chem Int Ed Engl 2020; 59:6383-6388. [PMID: 32011794 DOI: 10.1002/anie.201913394] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 01/13/2020] [Indexed: 11/11/2022]
Abstract
Nitrogen-containing polycyclic aromatic compounds (N-PACs) are an important class of compounds in materials science. Reported here is a new aza-annulative π-extension (aza-APEX) reaction that allows rapid access to a range of N-PACs in 11-84 % yields from readily available unfunctionalized aromatics and imidoyl chlorides. In the presence of silver hexafluorophosphate, arenes and imidoyl chlorides couple in a regioselective fashion. The follow-up oxidative treatment with p-chloranil affords structurally diverse N-PACs, which are very difficult to synthesize. DFT calculations reveal that the aza-APEX reaction proceeds through the formal [4+2] cycloaddition of an arene and an in situ generated diarylnitrilium salt, with sequential aromatizations having relatively low activation energies. Transformation of N-PACs into nitrogen-doped nanographenes and their photophysical properties are also described.
Collapse
Affiliation(s)
- Kou P Kawahara
- Graduate School of Science, Nagoya University, Chikusa, Nagoya, 464-8602, Japan
| | - Wataru Matsuoka
- Graduate School of Science, Nagoya University, Chikusa, Nagoya, 464-8602, Japan
| | - Hideto Ito
- Graduate School of Science, Nagoya University, Chikusa, Nagoya, 464-8602, Japan.,JST-ERATO, Itami Molecular Nanocarbon Project, Nagoya University, Chikusa, Nagoya, 464-8602, Japan
| | - Kenichiro Itami
- Graduate School of Science, Nagoya University, Chikusa, Nagoya, 464-8602, Japan.,JST-ERATO, Itami Molecular Nanocarbon Project, Nagoya University, Chikusa, Nagoya, 464-8602, Japan.,Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| |
Collapse
|
13
|
Kawahara KP, Matsuoka W, Ito H, Itami K. Synthesis of Nitrogen‐Containing Polyaromatics by Aza‐Annulative π‐Extension of Unfunctionalized Aromatics. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201913394] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kou P. Kawahara
- Graduate School of ScienceNagoya University Chikusa Nagoya 464-8602 Japan
| | - Wataru Matsuoka
- Graduate School of ScienceNagoya University Chikusa Nagoya 464-8602 Japan
| | - Hideto Ito
- Graduate School of ScienceNagoya University Chikusa Nagoya 464-8602 Japan
- JST-ERATOItami Molecular Nanocarbon ProjectNagoya University Chikusa Nagoya 464-8602 Japan
| | - Kenichiro Itami
- Graduate School of ScienceNagoya University Chikusa Nagoya 464-8602 Japan
- JST-ERATOItami Molecular Nanocarbon ProjectNagoya University Chikusa Nagoya 464-8602 Japan
- Institute of Transformative Bio-Molecules (WPI-ITbM)Nagoya University Chikusa Nagoya 464-8601 Japan
| |
Collapse
|
14
|
Schendera E, Unkel LN, Huyen Quyen PP, Salkewitz G, Hoffmann F, Villinger A, Brasholz M. Visible-Light-Mediated Aerobic Tandem Dehydrogenative Povarov/Aromatization Reaction: Synthesis of Isocryptolepines. Chemistry 2020; 26:269-274. [PMID: 31553081 PMCID: PMC6973160 DOI: 10.1002/chem.201903921] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Indexed: 01/25/2023]
Abstract
A metal‐free, photoinduced aerobic tandem amine dehydrogenation/Povarov cyclization/aromatization reaction between N‐aryl glycine esters and indoles leads to tetracyclic 11H‐indolo[3,2‐c]quinolines under mild conditions and with high yields. The reaction can be performed by using molecular iodine along with visible light, or by combining an organic photoredox catalyst with a halide anion. Mechanistic studies reveal that product formation occurs through a combination of radical‐mediated oxidation steps with an iminium ion or N‐haloiminium ion [4+2]‐cycloaddition, and the N‐heterocyclic products constitute new analogues of the antiplasmodial natural alkaloid isocryptolepine.
Collapse
Affiliation(s)
- Eva Schendera
- Institute of Chemistry, Organic Chemistry, University of Rostock, Albert-Einstein-Strasse 3A, 18059, Rostock, Germany
| | - Lisa-Natascha Unkel
- Institute of Chemistry, Organic Chemistry, University of Rostock, Albert-Einstein-Strasse 3A, 18059, Rostock, Germany
| | - Phung Phan Huyen Quyen
- Institute of Chemistry, Organic Chemistry, University of Rostock, Albert-Einstein-Strasse 3A, 18059, Rostock, Germany
| | - Gwen Salkewitz
- Institute of Chemistry, Organic Chemistry, University of Rostock, Albert-Einstein-Strasse 3A, 18059, Rostock, Germany
| | - Frank Hoffmann
- Department of Chemistry, Institute of Inorganic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Alexander Villinger
- Institute of Chemistry, Inorganic Chemistry, University of Rostock, Albert-Einstein-Strasse 3A, 18059, Rostock, Germany
| | - Malte Brasholz
- Institute of Chemistry, Organic Chemistry, University of Rostock, Albert-Einstein-Strasse 3A, 18059, Rostock, Germany
| |
Collapse
|
15
|
Bao X, Jiang W, Liang J, Huo C. One-electron oxidative dehydrogenative annulation and cyclization reactions. Org Chem Front 2020. [DOI: 10.1039/d0qo00422g] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This review focuses on the recent advances in one-electron oxidation involved oxidative dehydrogenative annulations and cyclizations for the intermolecular and intramolecular construction of valuable ring structures.
Collapse
Affiliation(s)
- Xiazhen Bao
- Gansu International Scientific and Technological Cooperation Base of Water-Retention Chemical Functional Materials
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou
- China
| | - Wei Jiang
- Gansu International Scientific and Technological Cooperation Base of Water-Retention Chemical Functional Materials
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou
- China
| | - Jia Liang
- Gansu International Scientific and Technological Cooperation Base of Water-Retention Chemical Functional Materials
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou
- China
| | - Congde Huo
- Gansu International Scientific and Technological Cooperation Base of Water-Retention Chemical Functional Materials
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou
- China
| |
Collapse
|
16
|
Schendera E, Villinger A, Brasholz M. Photoinduced iodine-mediated tandem dehydrogenative Povarov cyclisation/C–H oxygenation reactions. Org Biomol Chem 2020; 18:6912-6915. [DOI: 10.1039/d0ob01494j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Visible light and iodine mediate dehydrogenative imine [4+2]-cycloaddition/C–H oxygenation reactions to furnish highly functionalised 3-quinolones under metal-free conditions.
Collapse
Affiliation(s)
- Eva Schendera
- University of Rostock
- Institute of Chemistry
- 18055 Rostock
- Germany
| | | | - Malte Brasholz
- University of Rostock
- Institute of Chemistry
- 18055 Rostock
- Germany
| |
Collapse
|