1
|
Huang QH, Li SX, Kang JC, Liu RX, Li ZH, Xiong F, Ding TM, Zhang SY. Regioselective Electrooxidative [3+2] Annulation between Indole and Aniline Derivatives to Construct Functionalized Indolo[2,3- b]indoles. Org Lett 2024; 26:5657-5663. [PMID: 38941517 DOI: 10.1021/acs.orglett.4c01610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2024]
Abstract
A protocol for the electrooxidative [3+2] annulation to generate indolo[2,3-b]indoles in an undivided cell is reported. It exhibits good yields with excellent regioselectivities and tolerates various functional groups without external chemical oxidants. Cyclic voltammetry and density functional theory calculations indicate that the [3+2] annulation is initiated by the simultaneous anodic oxidation of indole and aniline derivatives, and the step to determine the rate relies on the combination of radical cations.
Collapse
Affiliation(s)
- Qing-Hong Huang
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Shuai-Xin Li
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jun-Chen Kang
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Ru-Xin Liu
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Zi-Hao Li
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Feng Xiong
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Tong-Mei Ding
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- Inner Mongolia Research Institute, Shanghai Jiao Tong University, Inner Mongolia 010052, P. R. China
| | - Shu-Yu Zhang
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| |
Collapse
|
2
|
Babu SA, A A, Mohan M, Paul N, Mathew J, John J. Tandem Reactions of Electrophilic Indoles toward Indolizines and Their Subsequent Transformations through Pd(II)-Mediated C-H Functionalization to Access Polyring-Fused N-Heterocycles. ACS OMEGA 2024; 9:16196-16206. [PMID: 38617644 PMCID: PMC11007710 DOI: 10.1021/acsomega.3c10194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 03/15/2024] [Accepted: 03/20/2024] [Indexed: 04/16/2024]
Abstract
A simple and efficient synthetic approach for generating a library of structurally novel indolizines has been developed via sequential 1,3-dipolar cycloaddition-ring opening processes. Using this methodology, a series of indolizines bearing different substituents were made in moderate to good yields. The presence of two functionalizable C-H bonds in these indolizine motifs makes them attractive for accessing fused indolizine scaffolds. In this line, we have introduced palladium-mediated site-selective C-H functionalizations, where the N-center and the two C-H centers of the indolizine moiety can be readily functionalized to generate fused N-heterocycles. Utilizing a Pd-mediated dual C-H activation of 5-benzoyl-substituted indolizine afforded 6H-indeno-indolizine, and a tetracene, viz., indolizino[2,1-b]indoles, was produced in the same substrate by the Pd-catalyzed selective C-H amination in the presence of oxygen.
Collapse
Affiliation(s)
- Sheba Ann Babu
- Chemical
Sciences and Technology Division, CSIR-National
Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Aparna A
- Chemical
Sciences and Technology Division, CSIR-National
Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
| | - Malavika Mohan
- Chemical
Sciences and Technology Division, CSIR-National
Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
| | - Namitha Paul
- Chemical
Sciences and Technology Division, CSIR-National
Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
| | - Jomon Mathew
- Research
and Post-Graduate Department of Chemistry, St. Joseph’s College, Devagiri, Calicut 673008, India
| | - Jubi John
- Chemical
Sciences and Technology Division, CSIR-National
Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| |
Collapse
|
3
|
Babu SA, E J, John J. Annulation reactions of electrophilic benzannulated heterocycles towards heteroacenes. Chem Commun (Camb) 2024; 60:1674-1689. [PMID: 38258327 DOI: 10.1039/d3cc05449g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The current review describes different annulation strategies reported with electrophilic benzannulated heterocycles for accessing heteroacenes. For the past two decades, the chemistry of electrophilic benzannulated heterocycles was extensively investigated, and several dipolar cycloadditions, metal and organo-catalyzed transformations were introduced for the generation of fused heterocycles. In this review, we have collected all the reports where the annulation of electrophilic benzannulated heterocycles results in a fully aromatic system, viz. heteroacenes with tri-, tetra-, and pentacyclic rings. We reviewed every paper on the synthesis of fused heterocycles that was accessible and categorized the review into several parts based on the electrophilic benzannulated heterocycle used in the heteroacene synthesis such as electrophilic indole, electrophilic benzothiophene, and so forth. The generality and mechanistic postulates of each methodology are highlighted. In addition, we have also tried to feature the advantages or shortcomings of each method and have mentioned the possible applications of these methodologies for accessing heteroacenes for material applications.
Collapse
Affiliation(s)
- Sheba Ann Babu
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram-695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India.
| | - Jijy E
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram-695019, India
- Department of Chemistry, MES College, Nedumkandam, Idukki, Kerala-685553, India.
| | - Jubi John
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram-695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India.
| |
Collapse
|
4
|
Babu SA, P V V, Poulose S, Varughese S, John J. Copper-Catalyzed Annulation of Electrophilic Benzannulated Heterocycles with 2-Aminopyridine and 2-Aminoquinoline: Direct Access toward Polyring-Fused Imidazo[1,2- a]pyridines. J Org Chem 2023; 88:10027-10039. [PMID: 37433107 DOI: 10.1021/acs.joc.3c00849] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2023]
Abstract
We have developed a direct method for the synthesis of polyring-fused imidazo[1,2-a]pyridines via a copper-catalyzed annulation of electrophilic benzannulated heterocycles with 2-aminopyridine and 2-aminoquinoline. From 3-nitroindoles and 2-aminopyridine, we could synthesize tetracenes, viz., indole-fused imidazo[1,2-a]pyridines, and by starting from 2-aminoquinoline, we could generate pentacenes, viz., indolo-imidazo[1,2-a]quinolines. In addition, we could also extend the methodology toward the synthesis of benzothieno-imidazo[1,2-a]pyridines starting from 3-nitrobenzothiophene. Furthermore, the basic photophysical properties of these synthesized heteroacenes were evaluated.
Collapse
Affiliation(s)
- Sheba Ann Babu
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Varsha P V
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
| | - Susanna Poulose
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sunil Varughese
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Jubi John
- Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| |
Collapse
|