A Facile Synthesis of 2-Oxazolines via Dehydrative Cyclization Promoted by Triflic Acid
2-oxazolines are common moieties in numerous natural products, pharmaceuticals, and functional copolymers. Current methods for synthesizing 2-oxazolines mainly rely on stoichiometric dehydration agents or catalytic dehydration promoted by specific catalysts. These conditions either generate stoichio...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-12-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/27/24/9042 |
| _version_ | 1797455998580948992 |
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| author | Tao Yang Chengjie Huang Jingyang Jia Fan Wu Feng Ni |
| author_facet | Tao Yang Chengjie Huang Jingyang Jia Fan Wu Feng Ni |
| author_sort | Tao Yang |
| collection | DOAJ |
| description | 2-oxazolines are common moieties in numerous natural products, pharmaceuticals, and functional copolymers. Current methods for synthesizing 2-oxazolines mainly rely on stoichiometric dehydration agents or catalytic dehydration promoted by specific catalysts. These conditions either generate stoichiometric amounts of waste or require forcing azeotropic reflux conditions. As such, a practical and robust method that promotes dehydrative cyclization while generating no byproducts would be attractive to oxazoline production. Herein, we report a triflic acid (TfOH)-promoted dehydrative cyclization of <i>N</i>-(2-hydroxyethyl)amides for synthesizing 2-oxazolines. This reaction tolerates various functional groups and generates water as the only byproduct. This method affords oxazoline with inversion of α-hydroxyl stereochemistry, suggesting that alcohol is activated as a leaving group under these conditions. Furthermore, the one-pot synthesis protocol of 2-oxazolines directly from carboxylic acids and amino alcohols is also provided. |
| first_indexed | 2024-03-09T16:02:10Z |
| format | Article |
| id | doaj.art-582016459d414de394567f5b3ac60fb5 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-09T16:02:10Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-582016459d414de394567f5b3ac60fb52023-11-24T17:01:49ZengMDPI AGMolecules1420-30492022-12-012724904210.3390/molecules27249042A Facile Synthesis of 2-Oxazolines via Dehydrative Cyclization Promoted by Triflic AcidTao Yang0Chengjie Huang1Jingyang Jia2Fan Wu3Feng Ni4Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, ChinaInstitute of Drug Discovery Technology, Ningbo University, Ningbo 315211, ChinaInstitute of Drug Discovery Technology, Ningbo University, Ningbo 315211, ChinaInstitute of Drug Discovery Technology, Ningbo University, Ningbo 315211, ChinaInstitute of Drug Discovery Technology, Ningbo University, Ningbo 315211, China2-oxazolines are common moieties in numerous natural products, pharmaceuticals, and functional copolymers. Current methods for synthesizing 2-oxazolines mainly rely on stoichiometric dehydration agents or catalytic dehydration promoted by specific catalysts. These conditions either generate stoichiometric amounts of waste or require forcing azeotropic reflux conditions. As such, a practical and robust method that promotes dehydrative cyclization while generating no byproducts would be attractive to oxazoline production. Herein, we report a triflic acid (TfOH)-promoted dehydrative cyclization of <i>N</i>-(2-hydroxyethyl)amides for synthesizing 2-oxazolines. This reaction tolerates various functional groups and generates water as the only byproduct. This method affords oxazoline with inversion of α-hydroxyl stereochemistry, suggesting that alcohol is activated as a leaving group under these conditions. Furthermore, the one-pot synthesis protocol of 2-oxazolines directly from carboxylic acids and amino alcohols is also provided.https://www.mdpi.com/1420-3049/27/24/90422-oxazolinesdehydrative cyclizationgreen synthesis |
| spellingShingle | Tao Yang Chengjie Huang Jingyang Jia Fan Wu Feng Ni A Facile Synthesis of 2-Oxazolines via Dehydrative Cyclization Promoted by Triflic Acid Molecules 2-oxazolines dehydrative cyclization green synthesis |
| title | A Facile Synthesis of 2-Oxazolines via Dehydrative Cyclization Promoted by Triflic Acid |
| title_full | A Facile Synthesis of 2-Oxazolines via Dehydrative Cyclization Promoted by Triflic Acid |
| title_fullStr | A Facile Synthesis of 2-Oxazolines via Dehydrative Cyclization Promoted by Triflic Acid |
| title_full_unstemmed | A Facile Synthesis of 2-Oxazolines via Dehydrative Cyclization Promoted by Triflic Acid |
| title_short | A Facile Synthesis of 2-Oxazolines via Dehydrative Cyclization Promoted by Triflic Acid |
| title_sort | facile synthesis of 2 oxazolines via dehydrative cyclization promoted by triflic acid |
| topic | 2-oxazolines dehydrative cyclization green synthesis |
| url | https://www.mdpi.com/1420-3049/27/24/9042 |
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