Upper Rim-Bridged Calix[4]arenes via Cyclization of <i>meta</i> Alkynyl Intermediates with Diphenyl Diselenide
A Sonogashira coupling of <i>meta</i>-iodocalix[4]arene with various terminal acetylenes confirmed that the <i>meta</i> position of calixarene is well addressable, and that both thermal and microwave protocols led to good yields of alkynylcalixarenes. Alkynes thus obtained we...
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MDPI AG
2024-03-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/29/6/1237 |
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| author | Anastasia Surina Karolína Salvadori Matěj Poupě Jan Čejka Ludmila Šimková Pavel Lhoták |
| author_facet | Anastasia Surina Karolína Salvadori Matěj Poupě Jan Čejka Ludmila Šimková Pavel Lhoták |
| author_sort | Anastasia Surina |
| collection | DOAJ |
| description | A Sonogashira coupling of <i>meta</i>-iodocalix[4]arene with various terminal acetylenes confirmed that the <i>meta</i> position of calixarene is well addressable, and that both thermal and microwave protocols led to good yields of alkynylcalixarenes. Alkynes thus obtained were subjected to the ferric chloride and diphenyl diselenide-promoted electrophilic closure. It turns out that the calix[4]arenes give completely different bridging products than those described for the non-macrocyclic starting compounds. This can be demonstrated not only by the isolation of products with a six-membered ring (<i>6-exo-dig</i>), but mainly by the smooth formation of the <i>5-endo-dig</i> cyclization, which has never been observed in the aliphatic series. An attempt at electrocyclization led to a high yield of the 1,2-diketone (oxidation of the starting alkyne), again in contrast to the reaction described for the acyclic derivatives. The structures of the unexpected products were unequivocally established by X-ray analysis and clearly demonstrate how the preorganized macrocyclic skeleton favors a completely different regioselectivity of cyclization reactions compared to common aliphatic compounds. |
| first_indexed | 2024-04-24T17:58:27Z |
| format | Article |
| id | doaj.art-8f49418fe42e4f42ace8d58766427c16 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-04-24T17:58:27Z |
| publishDate | 2024-03-01 |
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| series | Molecules |
| spelling | doaj.art-8f49418fe42e4f42ace8d58766427c162024-03-27T13:56:48ZengMDPI AGMolecules1420-30492024-03-01296123710.3390/molecules29061237Upper Rim-Bridged Calix[4]arenes via Cyclization of <i>meta</i> Alkynyl Intermediates with Diphenyl DiselenideAnastasia Surina0Karolína Salvadori1Matěj Poupě2Jan Čejka3Ludmila Šimková4Pavel Lhoták5Department of Organic Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague, Czech RepublicJ. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences v.v.i., Dolejškova 2155/3, 182 23 Prague, Czech RepublicDepartment of Organic Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague, Czech RepublicDepartment of Solid State Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague, Czech RepublicJ. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences v.v.i., Dolejškova 2155/3, 182 23 Prague, Czech RepublicDepartment of Organic Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague, Czech RepublicA Sonogashira coupling of <i>meta</i>-iodocalix[4]arene with various terminal acetylenes confirmed that the <i>meta</i> position of calixarene is well addressable, and that both thermal and microwave protocols led to good yields of alkynylcalixarenes. Alkynes thus obtained were subjected to the ferric chloride and diphenyl diselenide-promoted electrophilic closure. It turns out that the calix[4]arenes give completely different bridging products than those described for the non-macrocyclic starting compounds. This can be demonstrated not only by the isolation of products with a six-membered ring (<i>6-exo-dig</i>), but mainly by the smooth formation of the <i>5-endo-dig</i> cyclization, which has never been observed in the aliphatic series. An attempt at electrocyclization led to a high yield of the 1,2-diketone (oxidation of the starting alkyne), again in contrast to the reaction described for the acyclic derivatives. The structures of the unexpected products were unequivocally established by X-ray analysis and clearly demonstrate how the preorganized macrocyclic skeleton favors a completely different regioselectivity of cyclization reactions compared to common aliphatic compounds.https://www.mdpi.com/1420-3049/29/6/1237calixareneSonogashira coupling<i>meta</i>-substitutionalkyne cyclizationdiphenyl diselenide<i>6-exo-dig</i> and <i>5-endo-dig</i> cyclization |
| spellingShingle | Anastasia Surina Karolína Salvadori Matěj Poupě Jan Čejka Ludmila Šimková Pavel Lhoták Upper Rim-Bridged Calix[4]arenes via Cyclization of <i>meta</i> Alkynyl Intermediates with Diphenyl Diselenide Molecules calixarene Sonogashira coupling <i>meta</i>-substitution alkyne cyclization diphenyl diselenide <i>6-exo-dig</i> and <i>5-endo-dig</i> cyclization |
| title | Upper Rim-Bridged Calix[4]arenes via Cyclization of <i>meta</i> Alkynyl Intermediates with Diphenyl Diselenide |
| title_full | Upper Rim-Bridged Calix[4]arenes via Cyclization of <i>meta</i> Alkynyl Intermediates with Diphenyl Diselenide |
| title_fullStr | Upper Rim-Bridged Calix[4]arenes via Cyclization of <i>meta</i> Alkynyl Intermediates with Diphenyl Diselenide |
| title_full_unstemmed | Upper Rim-Bridged Calix[4]arenes via Cyclization of <i>meta</i> Alkynyl Intermediates with Diphenyl Diselenide |
| title_short | Upper Rim-Bridged Calix[4]arenes via Cyclization of <i>meta</i> Alkynyl Intermediates with Diphenyl Diselenide |
| title_sort | upper rim bridged calix 4 arenes via cyclization of i meta i alkynyl intermediates with diphenyl diselenide |
| topic | calixarene Sonogashira coupling <i>meta</i>-substitution alkyne cyclization diphenyl diselenide <i>6-exo-dig</i> and <i>5-endo-dig</i> cyclization |
| url | https://www.mdpi.com/1420-3049/29/6/1237 |
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