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Zhang SP, Guo DW, Yang ML, Xia YT, Yang WC. EDA Complex-Enabled Annulation to Access CF 2-Containing Tetralones and Quinazolinones Using Persulfates as Electron Donors. J Org Chem 2024; 89:10614-10623. [PMID: 39051432 DOI: 10.1021/acs.joc.4c00845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
A photocatalyst-free and EDA complex-enabled radical cascade cyclization reaction of inactive alkenes with bromodifluoroacetamides was reported for the divergent synthesis of fluorine-containing tetralones and quinazolinones. In this transformation, persulfates as electron donors and difluoro bromamide as electron acceptors generate the EDA complex. This is a promising photochemical method with advantages such as mild reaction conditions, simple operation, being metal-free, and excellent functional group tolerance.
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Affiliation(s)
- Shu-Peng Zhang
- Guangling College and School of Plant Protection, Yangzhou University, Yangzhou 225009, P. R. China
| | - Da-Wei Guo
- Guangling College and School of Plant Protection, Yangzhou University, Yangzhou 225009, P. R. China
| | - Mei-Ling Yang
- Guangling College and School of Plant Protection, Yangzhou University, Yangzhou 225009, P. R. China
| | - Yun-Tao Xia
- College of Chemistry & Chemical Engineering, Henan University of Technology, Academician Workstation for Natural Medicinal Chemistry of Henan Province, Zhengzhou 450001, China
| | - Wen-Chao Yang
- Guangling College and School of Plant Protection, Yangzhou University, Yangzhou 225009, P. R. China
- Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, Huaibei Normal University, Huaibei, Anhui 235000, P. R. China
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Bankura A, Ghosh S, Biswas S, Das I. Convergent Paired Electrolysis for [3+2] Cycloaddition of Azidotrimethylsilane with N-Heterocycles. CHEMSUSCHEM 2024:e202400381. [PMID: 38801175 DOI: 10.1002/cssc.202400381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/22/2024] [Accepted: 05/27/2024] [Indexed: 05/29/2024]
Abstract
A widely used method to obtain tetrazoles is through the azide and nitrile [3+2] cycloaddition. However, this process often involves using non-recyclable transition metals or Lewis acid catalysts and stoichiometric amounts of oxidants and additives, which reduces atom efficiency. We have discovered a convergent paired electrochemical reaction to perform this cycloaddition reaction, without the need for metal catalysts or oxidants. This tetrazolation strategy uses azidotrimethylsilane (TMSN3) and N-heterocycles in an undivided cell at a constant current. We use a mixture of CH3CN and equivalent amounts of H2O as co-solvent at room temperature. It is crucial to produce a stoichiometric amount of active hydroxyl ions through the cathodic reduction of water. Cyclic voltammetry (CV) studies and control experiments confirm that the cycloaddition reaction is specific to the electrode electron transfer process, eliminating the need for a mediator to shuttle electrons. This metal- and oxidant-free strategy is highly compatible with different functional groups and produces products with moderate to good yields. We have successfully tetrazolated bioactive compounds at a late stage, scaled up batches efficiently, and synthesized free amino-containing N-heterocycles via denitrogenation of tetrazoles.
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Affiliation(s)
- Abhijit Bankura
- Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology Jadavpur, Kolkata, 700032, India
| | - Subhadeep Ghosh
- Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology Jadavpur, Kolkata, 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sumit Biswas
- Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology Jadavpur, Kolkata, 700032, India
| | - Indrajit Das
- Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology Jadavpur, Kolkata, 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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Tang M, Draper F, Pham LN, Ho CC, Huang H, Sun J, Thickett SC, Coote ML, Connell TU, Bissember AC. Photochemical Povarov-type Reactions: Electron Donor-Acceptor Photoactivation by Visible Light. J Org Chem 2024; 89:2683-2690. [PMID: 38314706 DOI: 10.1021/acs.joc.3c02746] [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
This report investigates the mechanism of photochemical Povarov-type reactions of N,N-dialkylanilines and maleimides in polar solvents (DMF or dioxane) in the presence of light. Fundamental aspects of the electron donor-acceptor (EDA) photoactivation pathway proposed to underpin this chemistry are examined through integrated experimental and computational studies. This approach provided evidence supporting the involvement of an EDA complex in facilitating this chemistry via a reaction mechanism that does not involve a triplet manifold. Most notably, our findings indicate that relying solely on UV-vis absorption spectroscopic data to either account for or predict reactivity in synthetic experiments may not always provide the complete picture. More specifically, this relates to considering UV-vis absorption spectroscopic data, calculated values for association constants (KEDA) and molar extinction coefficients (ε), with the reactivity observed in associated synthetic reactions in practice.
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Affiliation(s)
- Meiqiong Tang
- School of Natural Sciences - Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Felicity Draper
- School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3220, Australia
| | - Le Nhan Pham
- Institute for Nanoscale Science and Technology, Flinders University, Adelaide, South Australia 5042, Australia
| | - Curtis C Ho
- School of Natural Sciences - Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Hai Huang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Jianwei Sun
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Stuart C Thickett
- School of Natural Sciences - Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Michelle L Coote
- Institute for Nanoscale Science and Technology, Flinders University, Adelaide, South Australia 5042, Australia
| | - Timothy U Connell
- School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3220, Australia
| | - Alex C Bissember
- School of Natural Sciences - Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
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