1
|
Kumar MP, G M, Amaladass P, Manikandan C, Dhayalan V. Recent synthetic strategies for the construction of functionalized carbazoles and their heterocyclic motifs enabled by Lewis acids. RSC Adv 2023; 13:32596-32626. [PMID: 37936643 PMCID: PMC10626344 DOI: 10.1039/d3ra06396h] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 10/25/2023] [Indexed: 11/09/2023] Open
Abstract
This article demonstrates recent innovative cascade annulation methods for preparing functionalized carbazoles and their related polyaromatic heterocyclic compounds enabled by Lewis acid catalysts. Highly substituted carbazole scaffolds were synthesized via Lewis acid mediated Friedel-Crafts arylation, electrocyclization, intramolecular cyclization, cycloaddition, C-N bond-formations, aromatization and cascade domino reactions, metal-catalyzed, iodine catalyzed reactions and multi-component reactions. This review article mainly focuses on Lewis acid-mediated recent synthetic methods to access a variety of electron-rich and electron-poor functional groups substituted carbazole frameworks in one-pot reactions. Polyaromatic carbazole and their related nitrogen-based heterocyclic compounds were found in several synthetic applications in pharma industries, energy devices, and materials sciences. Moreover, the review paper briefly summarised new synthetic strategies of carbazole preparation approaches will assist academic and pharma industries in identifying innovative protocols for producing poly-functionalized carbazoles and related highly complex heterocyclic compounds and discovering active pharmaceutical drugs or carbazole-based alkaloids and natural products.
Collapse
Affiliation(s)
- Marappan Pradeep Kumar
- Department of Chemistry, National Institute of Technology Puducherry Karaikal-609609 Union Territory Puducherry India https://vasudeva49.wixsite.com/catalysislab
| | - Mahantesh G
- Department of Chemistry, National Institute of Technology Puducherry Karaikal-609609 Union Territory Puducherry India https://vasudeva49.wixsite.com/catalysislab
| | - P Amaladass
- Department of Chemistry, Madanapalle Institute of Technology & Science Madanapalle 517325 Andhra Pradesh India
| | - Chitrarasu Manikandan
- Department of Chemistry, National Institute of Technology Puducherry Karaikal-609609 Union Territory Puducherry India https://vasudeva49.wixsite.com/catalysislab
| | - Vasudevan Dhayalan
- Department of Chemistry, National Institute of Technology Puducherry Karaikal-609609 Union Territory Puducherry India https://vasudeva49.wixsite.com/catalysislab
| |
Collapse
|
2
|
Greiner LC, Arichi N, Inuki S, Ohno H. Gold(I)-Catalyzed Benzylic C(sp 3 )-H Functionalizations: Divergent Synthesis of Indole[a]- and [b]-Fused Polycycles. Angew Chem Int Ed Engl 2023; 62:e202213653. [PMID: 36255174 DOI: 10.1002/anie.202213653] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/17/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022]
Abstract
Phenyl azides substituted by an (alkylphenyl)ethynyl group facilitate benzylic sp3 (C-H) functionalization in the presence of a JohnPhosAu catalyst, resulting in indole-fused tetra- and pentacycles via divergent N- or C-cyclization. The chemoselectivity is influenced depending on the counter-anion, the electron density of the α-imino gold(I) carbene, and the alkyl groups stabilizing the benzylic carbocation originating from a 1,5-hydride shift. An isotopic labeling experiment demonstrates the involvement of an indolylgold(I) species resulting from a tautomerization that is much faster than the deauration. The formation of a benzylic sp3 (C-H) functionalization leading to an indole-fused seven-membered ring is also demonstrated.
Collapse
Affiliation(s)
- Luca C Greiner
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Norihito Arichi
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Shinsuke Inuki
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Hiroaki Ohno
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| |
Collapse
|
3
|
Greiner LC, Inuki S, Arichi N, Oishi S, Suzuki R, Iwai T, Sawamura M, Hashmi ASK, Ohno H. Access to Indole-Fused Benzannulated Medium-Sized Rings through a Gold(I)-Catalyzed Cascade Cyclization of Azido-Alkynes. Chemistry 2021; 27:12992-12997. [PMID: 34110644 DOI: 10.1002/chem.202101824] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Indexed: 02/05/2023]
Abstract
Because benzannulated and indole-fused medium-sized rings are found in many bioactive compounds, combining these fragments might lead to unexplored areas of biologically relevant and uncovered chemical space. Herein is shown that α-imino gold carbene chemistry can play an important role in solving the difficulty in the formation of medium-sized rings. Namely, phenylene-tethered azido-alkynes undergo arylative cyclization through the formation of a gold carbene intermediate to afford benzannulated indole-fused medium-sized tetracycles. The reactions allow a range of different aryl substitution patterns and efficient access to these otherwise difficult-to-obtain medium-sized rings. This study also demonstrates the feasibility of the semihollow-shaped C-dtbm ligand for the construction of a nine-membered ring.
Collapse
Affiliation(s)
- Luca C Greiner
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Shinsuke Inuki
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Norihito Arichi
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Shinya Oishi
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan.,Current Address: Department of Medicinal Chemistry, Kyoto Pharmaceutical University, Yashima-ku, Kyoto, 607-8412, Japan
| | - Rikito Suzuki
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Tomohiro Iwai
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan.,Current Address: Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, 153-8902, Japan
| | - Masaya Sawamura
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - A Stephen K Hashmi
- Organisch-Chemisches Institut, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Hiroaki Ohno
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan
| |
Collapse
|
4
|
Greiner LC, Matsuoka J, Inuki S, Ohno H. Azido-Alkynes in Gold(I)-Catalyzed Indole Syntheses. CHEM REC 2021; 21:3897-3910. [PMID: 34498385 DOI: 10.1002/tcr.202100202] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/26/2021] [Indexed: 12/20/2022]
Abstract
The exploitation of nitrogen-functionalized reactive intermediates plays an important role in the synthesis of biologically relevant scaffolds in the field of pharmaceutical sciences. Those based on gold carbenes carry a strong potential for the design of highly efficient cascade processes toward the synthesis of compounds containing a fused indole core structure. This personal account gives a detailed explanation of our contribution to this sector, and embraces the reaction development of efficient gold-catalyzed cascade processes based on diversely functionalized azido-alkynes. Challenging cyclizations and their subsequent application in the synthesis of pharmaceutically relevant scaffolds and natural products conducted in an intra- or intermolecular fashion are key features of our research.
Collapse
Affiliation(s)
- Luca C Greiner
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Junpei Matsuoka
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan.,Current address: Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kodo, Kyotanabe, 610-0395, Japan
| | - Shinsuke Inuki
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Hiroaki Ohno
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| |
Collapse
|
5
|
Karan G, Sahu S, Maji MS. A one-pot "back-to-front" approach for the synthesis of benzene ring substituted indoles using allylboronic acids. Chem Commun (Camb) 2021; 57:5274-5277. [PMID: 33908966 DOI: 10.1039/d1cc01512e] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Synthesis of only benzene ring functionalized indoles and poly-substituted carbazoles is reported via a one-pot triple cascade benzannulation protocol. Usage of differently substituted and readily accessible allylboronic acids as a 3-carbon annulating partner enables diverse aliphatic and aromatic substitution patterns, which is still a daunting task. This scalable synthetic protocol tolerates broad scope, thus enabling further downstream modifications. As an application, carbazole based natural products glycozoline and glycozolinol were synthesized.
Collapse
Affiliation(s)
- Ganesh Karan
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, WB, India.
| | - Samrat Sahu
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, WB, India.
| | - Modhu Sudan Maji
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, WB, India.
| |
Collapse
|
6
|
Affiliation(s)
- Junpei Matsuoka
- Graduate School of Pharmaceutical Sciences, Kyoto University
| |
Collapse
|