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Teng Y, Fang T, Lin Z, Qin L, Jiang M, Wu W, You Y, Weng Z. Ring-expansion reaction for the synthesis of 2-(trifluoromethyl)oxazoles and 3-(trifluoromethyl)-1,2,4-triazines. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.154100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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2
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Jiao J, Nie W, Yu T, Yang F, Zhang Q, Aihemaiti F, Yang T, Liu X, Wang J, Li P. Multi-Step Continuous-Flow Organic Synthesis: Opportunities and Challenges. Chemistry 2021; 27:4817-4838. [PMID: 33034923 DOI: 10.1002/chem.202004477] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Indexed: 12/11/2022]
Abstract
Continuous-flow multi-step synthesis takes the advantages of microchannel flow chemistry and may transform the conventional multi-step organic synthesis by using integrated synthetic systems. To realize the goal, however, innovative chemical methods and techniques are urgently required to meet the significant remaining challenges. In the past few years, by using green reactions, telescoped chemical design, and/or novel in-line separation techniques, major and rapid advancement has been made in this direction. This minireview summarizes the most recent reports (2017-2020) on continuous-flow synthesis of functional molecules. Notably, several complex active pharmaceutical ingredients (APIs) have been prepared by the continuous-flow approach. Key technologies to the successes and remaining challenges are discussed. These results exemplified the feasibility of using modern continuous-flow chemistry for complex synthetic targets, and bode well for the future development of integrated, automated artificial synthetic systems.
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Affiliation(s)
- Jiao Jiao
- School of Chemistry, Xi'an Jiaotong University, Xi'an, 710061, P. R. China.,Xian Key Laboratory of Sustainable Energy Materials Chemistry, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Wenzheng Nie
- School of Chemistry, Xi'an Jiaotong University, Xi'an, 710061, P. R. China.,Xian Key Laboratory of Sustainable Energy Materials Chemistry, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Tao Yu
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Fan Yang
- Department of Applied Chemistry, Xi'an University of Technology, Xi'an, 710048, P. R. China
| | - Qian Zhang
- Department of Applied Chemistry, Xi'an University of Technology, Xi'an, 710048, P. R. China
| | - Feierdaiweisi Aihemaiti
- School of Chemistry, Xi'an Jiaotong University, Xi'an, 710061, P. R. China.,Xian Key Laboratory of Sustainable Energy Materials Chemistry, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Tingjun Yang
- School of Chemistry, Xi'an Jiaotong University, Xi'an, 710061, P. R. China.,Xian Key Laboratory of Sustainable Energy Materials Chemistry, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Xuanyu Liu
- School of Medicine, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Jiachen Wang
- School of Medicine, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Pengfei Li
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, P. R. China.,Xian Key Laboratory of Sustainable Energy Materials Chemistry, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
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Andresini M, Degannaro L, Luisi R. A sustainable strategy for the straightforward preparation of 2 H-azirines and highly functionalized NH-aziridines from vinyl azides using a single solvent flow-batch approach. Beilstein J Org Chem 2021; 17:203-209. [PMID: 33564330 PMCID: PMC7849244 DOI: 10.3762/bjoc.17.20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 12/29/2020] [Indexed: 02/04/2023] Open
Abstract
The reported flow-batch approach enables the easy preparation of 2H-azirines and their stereoselective transformation into highly functionalized NH-aziridines, starting from vinyl azides and organolithium compounds. The protocol has been developed using cyclopentyl methyl ether (CPME) as an environmentally benign solvent, resulting into a sustainable, safe and potentially automatable method for the synthesis of interesting strained compounds.
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Affiliation(s)
- Michael Andresini
- Flow Chemistry and Microreactor Technology FLAME-Lab, Department of Pharmacy - Drug Sciences, University of Bari "A. Moro", Via E. Orabona 4, Bari, 70125, Italy
| | - Leonardo Degannaro
- Flow Chemistry and Microreactor Technology FLAME-Lab, Department of Pharmacy - Drug Sciences, University of Bari "A. Moro", Via E. Orabona 4, Bari, 70125, Italy
| | - Renzo Luisi
- Flow Chemistry and Microreactor Technology FLAME-Lab, Department of Pharmacy - Drug Sciences, University of Bari "A. Moro", Via E. Orabona 4, Bari, 70125, Italy
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Harisha MB, Dhanalakshmi P, Suresh R, Kumar RR, Muthusubramanian S. Access to highly substituted oxazoles by the reaction of α-azidochalcone with potassium thiocyanate. Beilstein J Org Chem 2020; 16:2108-2118. [PMID: 32952727 PMCID: PMC7476590 DOI: 10.3762/bjoc.16.178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 08/21/2020] [Indexed: 12/27/2022] Open
Abstract
The reactivity of α-azidochalcones has been explored for the preparation of highly substituted oxazoles via a 2H-azirine intermediate. The azidochalcones, when treated with potassium thiocyanate in the presence of potassium persulfate, lead to 2,4,5-trisubstituted oxazoles in good yields. Incidentally, 2-aminothiazoles are the products when ferric nitrate is employed instead of persulfate in the above reaction.
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Affiliation(s)
- Mysore Bhyrappa Harisha
- Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India.,Eurofins-Advinus Limited, Phase II, Peenya Industrial Area, Bangalore-560 058, India
| | - Pandi Dhanalakshmi
- Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India.,Department of Inorganic and Physical Chemistry, Indian Institute of Science (IISc), Bangalore-560 012, India
| | - Rajendran Suresh
- Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India
| | - Raju Ranjith Kumar
- Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India
| | - Shanmugam Muthusubramanian
- Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai-625 021, Tamil Nadu, India
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Bracken C, Baumann M. Development of a Continuous Flow Photoisomerization Reaction Converting Isoxazoles into Diverse Oxazole Products. J Org Chem 2020; 85:2607-2617. [PMID: 31927926 DOI: 10.1021/acs.joc.9b03399] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A continuous flow process is presented, which directly converts isoxazoles into their oxazole counterparts via a photochemical transposition reaction. This results in the first reported exploitation of this transformation to establish its scope and synthetic utility. A series of various di- and trisubstituted oxazole products bearing different appendages including different heterocyclic moieties were realized through this rapid and mild flow process. Furthermore, the robustness of this approach was demonstrated by generating gram quantities of selected products while also providing insights into likely intermediates.
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Affiliation(s)
- Cormac Bracken
- School of Chemistry , University College Dublin , Science Centre South , Belfield, Dublin 4 , Ireland
| | - Marcus Baumann
- School of Chemistry , University College Dublin , Science Centre South , Belfield, Dublin 4 , Ireland
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Koo H, Kim HY, Oh K. Continuous Flow Synthesis of Isoxazoles via Vinyl Azides from Friedel–Crafts Acylation of Alkynes: A Modulated Troubleshooting Optimization Approach. Org Lett 2019; 21:10063-10068. [DOI: 10.1021/acs.orglett.9b04010] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Hyungmo Koo
- Center for Metareceptome Research, College of Pharmacy, Chung-Ang University, 84 Heukseok-ro, Dongjak, Seoul 06974, Republic of Korea
| | - Hun Young Kim
- Center for Metareceptome Research, College of Pharmacy, Chung-Ang University, 84 Heukseok-ro, Dongjak, Seoul 06974, Republic of Korea
| | - Kyungsoo Oh
- Center for Metareceptome Research, College of Pharmacy, Chung-Ang University, 84 Heukseok-ro, Dongjak, Seoul 06974, Republic of Korea
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Shen MH, Liang XC, Li C, Wu H, Qu HY, Wang FM, Xu HD. Rhodium promoted intramolecular [4 + 2] cycloaddition of 2-azidodiene with alkyne: A transition metal catalysis approach to challenging fused bicyclic vinyl azide. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2019.03.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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