Hydrogen bonding phase-transfer catalysis with ionic reactants: enantioselective synthesis of γ-fluoroamines
Ammonium salts are used as phase-transfer catalysts for fluorination with alkali metal fluoride. We now demonstrate that these organic salts, specifically azetidinium triflates, are suitable substrates for enantioselective ring opening with CsF and a chiral bis-urea catalyst. This process that highl...
| Main Authors: | , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
American Chemical Society
2020
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| _version_ | 1797067925670068224 |
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| author | Roagna, G Ascough, DMH Ibba, F Vicini, AC Fontana, A Christensen, KE Peschiulli, A Oehlrich, D Misale, A Trabanco, AA Paton, RS Pupo, G Gouverneur, V |
| author_facet | Roagna, G Ascough, DMH Ibba, F Vicini, AC Fontana, A Christensen, KE Peschiulli, A Oehlrich, D Misale, A Trabanco, AA Paton, RS Pupo, G Gouverneur, V |
| author_sort | Roagna, G |
| collection | OXFORD |
| description | Ammonium salts are used as phase-transfer catalysts for fluorination with alkali metal fluoride. We now demonstrate that these organic salts, specifically azetidinium triflates, are suitable substrates for enantioselective ring opening with CsF and a chiral bis-urea catalyst. This process that highlights the ability of hydrogen bonding phase-transfer catalysts to couple two ionic reactants, affords enantioenriched γ-fluoroamines in high yields. Mechanistic studies underline the role of the catalyst for phase-transfer, and computed transition state structures account for the enantioconvergence observed for mixtures of achiral azetidinium diastereomers. The N-substituents in the electrophile influence reactivity, but the configuration at nitrogen is unimportant for enantioselectivity.
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| first_indexed | 2024-03-06T22:03:24Z |
| format | Journal article |
| id | oxford-uuid:4f5b6c3a-7e0c-47b5-8662-65e715cc9111 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:03:24Z |
| publishDate | 2020 |
| publisher | American Chemical Society |
| record_format | dspace |
| spelling | oxford-uuid:4f5b6c3a-7e0c-47b5-8662-65e715cc91112022-03-26T16:06:45ZHydrogen bonding phase-transfer catalysis with ionic reactants: enantioselective synthesis of γ-fluoroaminesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4f5b6c3a-7e0c-47b5-8662-65e715cc9111EnglishSymplectic ElementsAmerican Chemical Society2020Roagna, GAscough, DMHIbba, FVicini, ACFontana, AChristensen, KEPeschiulli, AOehlrich, DMisale, ATrabanco, AAPaton, RSPupo, GGouverneur, VAmmonium salts are used as phase-transfer catalysts for fluorination with alkali metal fluoride. We now demonstrate that these organic salts, specifically azetidinium triflates, are suitable substrates for enantioselective ring opening with CsF and a chiral bis-urea catalyst. This process that highlights the ability of hydrogen bonding phase-transfer catalysts to couple two ionic reactants, affords enantioenriched γ-fluoroamines in high yields. Mechanistic studies underline the role of the catalyst for phase-transfer, and computed transition state structures account for the enantioconvergence observed for mixtures of achiral azetidinium diastereomers. The N-substituents in the electrophile influence reactivity, but the configuration at nitrogen is unimportant for enantioselectivity. |
| spellingShingle | Roagna, G Ascough, DMH Ibba, F Vicini, AC Fontana, A Christensen, KE Peschiulli, A Oehlrich, D Misale, A Trabanco, AA Paton, RS Pupo, G Gouverneur, V Hydrogen bonding phase-transfer catalysis with ionic reactants: enantioselective synthesis of γ-fluoroamines |
| title | Hydrogen bonding phase-transfer catalysis with ionic reactants: enantioselective synthesis of γ-fluoroamines |
| title_full | Hydrogen bonding phase-transfer catalysis with ionic reactants: enantioselective synthesis of γ-fluoroamines |
| title_fullStr | Hydrogen bonding phase-transfer catalysis with ionic reactants: enantioselective synthesis of γ-fluoroamines |
| title_full_unstemmed | Hydrogen bonding phase-transfer catalysis with ionic reactants: enantioselective synthesis of γ-fluoroamines |
| title_short | Hydrogen bonding phase-transfer catalysis with ionic reactants: enantioselective synthesis of γ-fluoroamines |
| title_sort | hydrogen bonding phase transfer catalysis with ionic reactants enantioselective synthesis of γ fluoroamines |
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