1
|
Laru S, Ghoshal S, Sarkar P, Hajra A. Unusual Regioselective C-H Difluoroalkylation of Heteroarenes under Photoredox Catalysis. Org Lett 2024; 26:5098-5104. [PMID: 38847562 DOI: 10.1021/acs.orglett.4c01323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
We disclose a new general strategy for the site-selective difluoroalkylation of nonprefunctionalized heteroarenes, such as quinoxaline at the C-8 position, and benzothiadiazole, benzoxadiazole, and benzothiazole at the C-4 position via consecutive organophotoredox-catalyzed radical-radical cross-coupling and base-assisted hydrogen abstraction reactions. The current methodology represents a site-selective direct difluoroalkylative strategy to allow broad functional group tolerance and a wide substrate scope in good to excellent yields. Careful experimental investigations and detailed DFT calculations revealed the exact site-selectivity of the heteroarenes and a possible mechanistic pathway.
Collapse
Affiliation(s)
- Sudip Laru
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan-731235, India
| | - Sourav Ghoshal
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan-731235, India
| | - Pranab Sarkar
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan-731235, India
| | - Alakananda Hajra
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan-731235, India
| |
Collapse
|
2
|
Xu G, Lv J, Ding Q, Ma C, Jiang Y, Yu B. Direct C-H Alkylation of Benzothiadiazoles via Organic Photoredox Catalysis. J Org Chem 2024; 89:2777-2781. [PMID: 38315024 DOI: 10.1021/acs.joc.3c02307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
2,1,3-Benzothiadiazole is widely used as a privileged scaffold in pharmaceuticals and organic functional materials. Nonetheless, many current methods for the functionalization of 2,1,3-benzothiadiazole rely on preactivation, transition metal catalysts/promoters, or an elevated reaction temperature. Herein we disclose a transition-metal-free visible-light-induced photocatalytic method for the direct C-H alkylation of 2,1,3-benzothiadiazole using readily accessible carboxylic acid derivatives, i.e., N-hydroxyphthalimide esters (NHPEs), as alkylating reagents under room temperature. This mild and scalable method is highlighted by the late-stage installation of the benzothiadiazole scaffold in drugs and natural products.
Collapse
Affiliation(s)
- Guiqing Xu
- Collaborative Innovation Centre of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Engineering Research Centre of Chiral Hydroxyl Pharmaceutical, Henan Engineering Laboratory of Chemical Pharmaceutical and Biomedical Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Jiayuan Lv
- Collaborative Innovation Centre of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Engineering Research Centre of Chiral Hydroxyl Pharmaceutical, Henan Engineering Laboratory of Chemical Pharmaceutical and Biomedical Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Qingjie Ding
- Collaborative Innovation Centre of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Engineering Research Centre of Chiral Hydroxyl Pharmaceutical, Henan Engineering Laboratory of Chemical Pharmaceutical and Biomedical Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Chunhua Ma
- Collaborative Innovation Centre of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Engineering Research Centre of Chiral Hydroxyl Pharmaceutical, Henan Engineering Laboratory of Chemical Pharmaceutical and Biomedical Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Yuqin Jiang
- Collaborative Innovation Centre of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Engineering Research Centre of Chiral Hydroxyl Pharmaceutical, Henan Engineering Laboratory of Chemical Pharmaceutical and Biomedical Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Bing Yu
- Green Catalysis Centre, College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China
| |
Collapse
|