{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,9]],"date-time":"2025-11-09T10:53:28Z","timestamp":1762685608472,"version":"build-2065373602"},"reference-count":41,"publisher":"Wiley","issue":"37","license":[{"start":{"date-parts":[[2017,10,9]],"date-time":"2017-10-09T00:00:00Z","timestamp":1507507200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"funder":[{"name":"National Portuguese NMR Network","award":["RECI\/BBB-BQB\/0230\/2012"],"award-info":[{"award-number":["RECI\/BBB-BQB\/0230\/2012"]}]},{"name":"FCT postdoctoral grant","award":["SFRH\/BPD\/84805\/2012"],"award-info":[{"award-number":["SFRH\/BPD\/84805\/2012"]}]},{"name":"the Associated Laboratory for Sustainable Chemistry-Clean Processes","award":["UID\/QUI\/50006\/2013"],"award-info":[{"award-number":["UID\/QUI\/50006\/2013"]}]},{"name":"Technologies-LAQV","award":["POCI-01-0145- FEDER-007265"],"award-info":[{"award-number":["POCI-01-0145- FEDER-007265"]}]},{"name":"research assistant contract","award":["NORTE-01-0145-FEDER-000011"],"award-info":[{"award-number":["NORTE-01-0145-FEDER-000011"]}]}],"content-domain":{"domain":["chemistry-europe.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Eur J Org Chem"],"published-print":{"date-parts":[[2017,10,10]]},"abstract":"<jats:p>8\u2010Phenyl\u20105,7\u2010dihydroxyflavylium and 8\u2010methyl\u20105,7\u2010dihydroxyflavylium were synthesized to observe the 6,8\u2010rearrangement. 8\u2010Phenyl and 8\u2010methyl residues were introduced by Suzuki\u2013Miyaura reaction of 8\u2010iodochrysin, then reduced by LiAlH<jats:sub>4<\/jats:sub> to give the corresponding 3\u2010deoxyanthocyanidins. At pH 1.0 the stable form is the 8\u2010substituted flavylium cation in both compounds. At higher pH values the quinoidal bases are the stable species and some evidence for the 6,8\u2010rearrangement was obtained, but the respective spectral variations are very small. This was overcome by using a modified cyclodextrin (captisol), which favors the formation of the <jats:italic>trans<\/jats:italic>\u2010chalcone at the expense of the quinoidal bases. The <jats:italic>trans<\/jats:italic>\u2010chalcone was isolated and dissolved in CD<jats:sub>3<\/jats:sub>OD\/DCl (pD &lt; 1) to give a mixture of the two flavylium isomers. This was confirmed by ESI\u2010MS analysis (recorded in positive ion mode) of the two isomers after separation by HPLC, which gave the same peak ([M]<jats:sup>+<\/jats:sup> <jats:italic>m\/z<\/jats:italic> 253). The 6\u2010isomer slowly reverts to the most stable 8\u2010isomer. The 6,8\u2010rearrangement was also observed after irradiation of the <jats:italic>trans<\/jats:italic>\u2010chalcone (in the presence of captisol) at pH 5. Acidification of this photostationary state gave a mixture of both flavylium cations. The UV\/Vis absorption of the flavylium cation (6\u2010isomer) was blueshifted in comparison to the 8\u2010isomer.<\/jats:p>","DOI":"10.1002\/ejoc.201701009","type":"journal-article","created":{"date-parts":[[2017,8,21]],"date-time":"2017-08-21T05:06:36Z","timestamp":1503291996000},"page":"5617-5626","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Unveiling the 6,8\u2010Rearrangement in 8\u2010Phenyl\u20105,7\u2010dihydroxyflavylium and 8\u2010Methyl\u20105,7\u2010dihydroxyflavylium through Host\u2013Guest Complexation"],"prefix":"10.1002","volume":"2017","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0121-3695","authenticated-orcid":false,"given":"Nuno","family":"Bas\u00edlio","sequence":"first","affiliation":[{"name":"LAQV REQUIMTE Departamento de Qu\u00edmica Faculdade de Ci\u00eancias e Tecnologia Universidade Nova de Lisboa  2829\u2010516 Caparica Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0528-1967","authenticated-orcid":false,"given":"Jo\u00e3o Carlos","family":"Lima","sequence":"additional","affiliation":[{"name":"LAQV REQUIMTE Departamento de Qu\u00edmica Faculdade de Ci\u00eancias e Tecnologia Universidade Nova de Lisboa  2829\u2010516 Caparica Portugal"}]},{"given":"Lu\u00eds","family":"Cruz","sequence":"additional","affiliation":[{"name":"REQUIMTE\/LAQV Departamento de Qu\u00edmica e Bioqu\u00edmica Faculdade de Ci\u00eancias e Tecnologia Universidade do Porto  Rua do Campo Alegre 687 4169\u2010007 Porto Portugal"}]},{"given":"Victor","family":"de Freitas","sequence":"additional","affiliation":[{"name":"REQUIMTE\/LAQV Departamento de Qu\u00edmica e Bioqu\u00edmica Faculdade de Ci\u00eancias e Tecnologia Universidade do Porto  Rua do Campo Alegre 687 4169\u2010007 Porto Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8529-6848","authenticated-orcid":false,"given":"Fernando","family":"Pina","sequence":"additional","affiliation":[{"name":"LAQV REQUIMTE Departamento de Qu\u00edmica Faculdade de Ci\u00eancias e Tecnologia Universidade Nova de Lisboa  2829\u2010516 Caparica Portugal"}]},{"given":"Hiroki","family":"Ando","sequence":"additional","affiliation":[{"name":"Graduate School of Information Sciences Nagoya University  464\u20108601 Chikusa, Nagoya Japan"}]},{"given":"Yuki","family":"Kimura","sequence":"additional","affiliation":[{"name":"Graduate School of Information Sciences Nagoya University  464\u20108601 Chikusa, Nagoya Japan"}]},{"given":"Kin\u2010Ichi","family":"Oyama","sequence":"additional","affiliation":[{"name":"Chemical Instrumentation Facility Research Center for Materials Science Nagoya University  464\u20108602 Chikusa, Nagoya Japan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1238-6348","authenticated-orcid":false,"given":"Kumi","family":"Yoshida","sequence":"additional","affiliation":[{"name":"Graduate School of Informatics Nagoya University  464\u20108601 Chikusa Japan"}]}],"member":"311","published-online":{"date-parts":[[2017,10,9]]},"reference":[{"key":"e_1_2_6_2_1","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1007\/978-1-4899-2913-6_16","volume-title":"The Flavonoids Advances in Research Since 1980","author":"Brouillard R.","year":"1988"},{"key":"e_1_2_6_2_2","first-page":"471","volume-title":"Flavonoids. Chemistry, Biochemistry and Application","author":"Anderson \u00d8. M.","year":"2006"},{"key":"e_1_2_6_3_1","doi-asserted-by":"publisher","DOI":"10.1039\/C1CS15126F"},{"key":"e_1_2_6_4_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00468a015"},{"key":"e_1_2_6_5_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00487a041"},{"key":"e_1_2_6_6_1","doi-asserted-by":"publisher","DOI":"10.1139\/v90-119"},{"key":"e_1_2_6_7_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00538a024"},{"key":"e_1_2_6_8_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja9704646"},{"volume-title":"Recent Advanced in Polyphenols Research","year":"2014","author":"Pina F.","key":"e_1_2_6_9_1"},{"key":"e_1_2_6_9_2","doi-asserted-by":"publisher","DOI":"10.1002\/open.201500210"},{"key":"e_1_2_6_10_1","unstructured":"See ref."},{"key":"e_1_2_6_11_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo01039a027"},{"key":"e_1_2_6_12_1","doi-asserted-by":"publisher","DOI":"10.1021\/jf900759q"},{"key":"e_1_2_6_13_1","doi-asserted-by":"publisher","DOI":"10.1039\/CT9252701128"},{"key":"e_1_2_6_13_2","doi-asserted-by":"publisher","DOI":"10.1055\/s-2003-40982"},{"key":"e_1_2_6_14_1","doi-asserted-by":"publisher","DOI":"10.1039\/jr9470000346"},{"key":"e_1_2_6_14_2","doi-asserted-by":"publisher","DOI":"10.1039\/jr9580004040"},{"key":"e_1_2_6_14_3","first-page":"1223","author":"Kueny\u2010Stotz M.","year":"2007","journal-title":"Synlett"},{"key":"e_1_2_6_14_4","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.200601071"},{"key":"e_1_2_6_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/0040-4020(77)88025-3"},{"key":"e_1_2_6_16_1","doi-asserted-by":"publisher","DOI":"10.1021\/ol0500463"},{"key":"e_1_2_6_16_2","doi-asserted-by":"publisher","DOI":"10.1021\/acs.jnatprod.6b00474"},{"key":"e_1_2_6_17_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF02976703"},{"key":"e_1_2_6_17_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF02980059"},{"key":"e_1_2_6_17_3","doi-asserted-by":"publisher","DOI":"10.1080\/00397910802710682"},{"key":"e_1_2_6_17_4","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejmech.2011.04.044"},{"key":"e_1_2_6_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.tetlet.2017.01.065"},{"key":"e_1_2_6_18_2","doi-asserted-by":"publisher","DOI":"10.3390\/ijms18020427"},{"key":"e_1_2_6_19_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.tetlet.2013.09.051"},{"key":"e_1_2_6_20_1","doi-asserted-by":"publisher","DOI":"10.3184\/174751914X13899617275193"},{"key":"e_1_2_6_21_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.bmc.2009.03.032"},{"key":"e_1_2_6_22_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo0343331"},{"key":"e_1_2_6_23_1","doi-asserted-by":"publisher","DOI":"10.1002\/adsc.200505405"},{"key":"e_1_2_6_24_1","unstructured":"%Ct =KhKtKi\/K\u2032a*100 \u2248 (K\u2032a\u2013Ka)\/K\u2032a*100."},{"key":"e_1_2_6_25_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00390a033"},{"key":"e_1_2_6_25_2","doi-asserted-by":"publisher","DOI":"10.1039\/C3NJ01271A"},{"key":"e_1_2_6_26_1","doi-asserted-by":"publisher","DOI":"10.1021\/acs.jafc.5b00765"},{"key":"e_1_2_6_26_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp4060582"},{"key":"e_1_2_6_27_1","unstructured":"The numeration of the flavylium cation is used and not the one of the chalcones to avoid misunderstandings."},{"key":"e_1_2_6_28_1","doi-asserted-by":"publisher","DOI":"10.3390\/molecules21111502"},{"key":"e_1_2_6_29_1","doi-asserted-by":"publisher","DOI":"10.1021\/ed074p1314"}],"container-title":["European Journal of Organic Chemistry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fejoc.201701009","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/ejoc.201701009","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,15]],"date-time":"2025-10-15T16:59:17Z","timestamp":1760547557000},"score":1,"resource":{"primary":{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/10.1002\/ejoc.201701009"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,10,9]]},"references-count":41,"journal-issue":{"issue":"37","published-print":{"date-parts":[[2017,10,10]]}},"alternative-id":["10.1002\/ejoc.201701009"],"URL":"https:\/\/doi.org\/10.1002\/ejoc.201701009","archive":["Portico"],"relation":{},"ISSN":["1434-193X","1099-0690"],"issn-type":[{"type":"print","value":"1434-193X"},{"type":"electronic","value":"1099-0690"}],"subject":[],"published":{"date-parts":[[2017,10,9]]},"assertion":[{"value":"2017-07-19","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2017-10-09","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}