Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones
Autor(a) principal: | |
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Data de Publicação: | 2009 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10198/3221 |
Resumo: | A large number of hydroxylated 2,3-diaryl-9H-xanthen-9- ones have been synthesised by two different approaches, starting either from 3-bromo-2-methyl-4H-chromen-4-one or from (E)-3-bromo-2-styryl-4H-chromen-4-ones. The former method involves Heck reactions between 3-bromo-2-methyl- 4H-chromen-4-one and styrenes, leading to (E)-2-methyl-3- styryl-4H-chromen-4-ones; these condensed with benzaldehyde to give (E,E)-2,3-distyryl-4H-chromen-4-ones, which led to the desired 2,3-diaryl-9H-xanthen-9-ones under reflux in 1,2,4-trichlorobenzene. 3-Bromo-2-styryl-4H-chromen-4- ones were obtained either by aldol condensations between 3-bromo-2-methyl-4H-chromen-4-one and benzaldehydes, or through Baker–Venkataraman rearrangements of 2-acetylphenyl cinnamates, followed by one-pot bromination/ cyclisation with phenyltrimethylammonium tribromide. The 2,3-diaryl-9H-xanthene-9-ones were obtained in one-pot transformations involving Heck reactions between (E)-3- Introduction Xanthones constitute one of the major classes of naturally occurring oxygen-containing heterocyclic compounds containing dibenzo-γ-pyrone rings.[1] They occur in two major plant families, Guttiferae and Gentianaceae, and also in some families of fungi and lichens.[2,3] Natural derivatives can be hydroxylated, methoxylated or prenylated, among other possibilities; the parent compound xanthone itself is not known as a natural product.[3,4] The presence of aryl groups on the xanthone core has only been reported for a few synthetic derivatives, and as far as we know the literature had never presented the synthesis of xanthones featuring 2,3-diaryl moieties before our work.[5,6] Over the last decades these substances have been extensively studied not only because they participate in several biological functions but also as a consequence of their remarkable antifungal,[7–9] anti-inflammatory,[10,11] antimalarial[ 12–14] and antitumour activities,[15,16] and even as promising antioxidant agents.[17–19] Structure–activity stud- [a] Department of Vegetal Production and Technology, Escola Superior Agrária de Bragança, 5301-855 Bragança, Portugal Fax: +351-273-325405 E-mail: clems@ipb.pt [b] Department of Chemistry & QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal Fax: +351-234-370084 E-mail: artur.silva@ua.pt © 2009 Wiley-VCH Verlag GmbH 2642 & Co. KGaA, Weinheim Eur. J. Org. Chem. 2009, 2642–2660 bromo-2-styryl-4H-chromen-4-ones and styrenes, followed by electrocyclisation and oxidation processes. The 2,3-diaryl- 3,4-dihydro-9H-xanthene-9-one intermediates were also isolated under these conditions, and so when 5-methoxy-2-styryl- 4H-chromen-4-ones were used as starting materials the 1-hydroxy-6,7-diaryl-9H-xanthene-9-ones were also observed. The second method is a general one, because it allowed the synthesis of a great number of 2,3-diaryl-9Hxanthen- 9-ones with several substitution patterns, whereas the first one is limited to certain derivatives. The last step in the synthesis of hydroxylated 2,3-diaryl-9H-xanthen-9-ones was the cleavage of the hydroxy protecting groups with boron tribromide. The structures and stereochemistry of all new compounds were established by NMR studies. |
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Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-onesXanthonesAlcoholsOxygen heterocyclesHeck reactionNMR spectroscopyA large number of hydroxylated 2,3-diaryl-9H-xanthen-9- ones have been synthesised by two different approaches, starting either from 3-bromo-2-methyl-4H-chromen-4-one or from (E)-3-bromo-2-styryl-4H-chromen-4-ones. The former method involves Heck reactions between 3-bromo-2-methyl- 4H-chromen-4-one and styrenes, leading to (E)-2-methyl-3- styryl-4H-chromen-4-ones; these condensed with benzaldehyde to give (E,E)-2,3-distyryl-4H-chromen-4-ones, which led to the desired 2,3-diaryl-9H-xanthen-9-ones under reflux in 1,2,4-trichlorobenzene. 3-Bromo-2-styryl-4H-chromen-4- ones were obtained either by aldol condensations between 3-bromo-2-methyl-4H-chromen-4-one and benzaldehydes, or through Baker–Venkataraman rearrangements of 2-acetylphenyl cinnamates, followed by one-pot bromination/ cyclisation with phenyltrimethylammonium tribromide. The 2,3-diaryl-9H-xanthene-9-ones were obtained in one-pot transformations involving Heck reactions between (E)-3- Introduction Xanthones constitute one of the major classes of naturally occurring oxygen-containing heterocyclic compounds containing dibenzo-γ-pyrone rings.[1] They occur in two major plant families, Guttiferae and Gentianaceae, and also in some families of fungi and lichens.[2,3] Natural derivatives can be hydroxylated, methoxylated or prenylated, among other possibilities; the parent compound xanthone itself is not known as a natural product.[3,4] The presence of aryl groups on the xanthone core has only been reported for a few synthetic derivatives, and as far as we know the literature had never presented the synthesis of xanthones featuring 2,3-diaryl moieties before our work.[5,6] Over the last decades these substances have been extensively studied not only because they participate in several biological functions but also as a consequence of their remarkable antifungal,[7–9] anti-inflammatory,[10,11] antimalarial[ 12–14] and antitumour activities,[15,16] and even as promising antioxidant agents.[17–19] Structure–activity stud- [a] Department of Vegetal Production and Technology, Escola Superior Agrária de Bragança, 5301-855 Bragança, Portugal Fax: +351-273-325405 E-mail: clems@ipb.pt [b] Department of Chemistry & QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal Fax: +351-234-370084 E-mail: artur.silva@ua.pt © 2009 Wiley-VCH Verlag GmbH 2642 & Co. KGaA, Weinheim Eur. J. Org. Chem. 2009, 2642–2660 bromo-2-styryl-4H-chromen-4-ones and styrenes, followed by electrocyclisation and oxidation processes. The 2,3-diaryl- 3,4-dihydro-9H-xanthene-9-one intermediates were also isolated under these conditions, and so when 5-methoxy-2-styryl- 4H-chromen-4-ones were used as starting materials the 1-hydroxy-6,7-diaryl-9H-xanthene-9-ones were also observed. The second method is a general one, because it allowed the synthesis of a great number of 2,3-diaryl-9Hxanthen- 9-ones with several substitution patterns, whereas the first one is limited to certain derivatives. The last step in the synthesis of hydroxylated 2,3-diaryl-9H-xanthen-9-ones was the cleavage of the hydroxy protecting groups with boron tribromide. The structures and stereochemistry of all new compounds were established by NMR studies.WileyBiblioteca Digital do IPBSantos, Clementina M.M.Silva, ArturCavaleiro, José2011-02-01T10:31:52Z20092009-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10198/3221engSantos, Clementina; Silva, Artur; Cavaleiro, José (2009). Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones. European Journal of Organic Chemistry. ISSN 1434-193X. 16, p. 2642-26601434-193X10.1002/ejoc.200900026info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-11-21T10:08:20Zoai:bibliotecadigital.ipb.pt:10198/3221Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T22:56:08.362092Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones |
title |
Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones |
spellingShingle |
Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones Santos, Clementina M.M. Xanthones Alcohols Oxygen heterocycles Heck reaction NMR spectroscopy |
title_short |
Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones |
title_full |
Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones |
title_fullStr |
Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones |
title_full_unstemmed |
Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones |
title_sort |
Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones |
author |
Santos, Clementina M.M. |
author_facet |
Santos, Clementina M.M. Silva, Artur Cavaleiro, José |
author_role |
author |
author2 |
Silva, Artur Cavaleiro, José |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
Biblioteca Digital do IPB |
dc.contributor.author.fl_str_mv |
Santos, Clementina M.M. Silva, Artur Cavaleiro, José |
dc.subject.por.fl_str_mv |
Xanthones Alcohols Oxygen heterocycles Heck reaction NMR spectroscopy |
topic |
Xanthones Alcohols Oxygen heterocycles Heck reaction NMR spectroscopy |
description |
A large number of hydroxylated 2,3-diaryl-9H-xanthen-9- ones have been synthesised by two different approaches, starting either from 3-bromo-2-methyl-4H-chromen-4-one or from (E)-3-bromo-2-styryl-4H-chromen-4-ones. The former method involves Heck reactions between 3-bromo-2-methyl- 4H-chromen-4-one and styrenes, leading to (E)-2-methyl-3- styryl-4H-chromen-4-ones; these condensed with benzaldehyde to give (E,E)-2,3-distyryl-4H-chromen-4-ones, which led to the desired 2,3-diaryl-9H-xanthen-9-ones under reflux in 1,2,4-trichlorobenzene. 3-Bromo-2-styryl-4H-chromen-4- ones were obtained either by aldol condensations between 3-bromo-2-methyl-4H-chromen-4-one and benzaldehydes, or through Baker–Venkataraman rearrangements of 2-acetylphenyl cinnamates, followed by one-pot bromination/ cyclisation with phenyltrimethylammonium tribromide. The 2,3-diaryl-9H-xanthene-9-ones were obtained in one-pot transformations involving Heck reactions between (E)-3- Introduction Xanthones constitute one of the major classes of naturally occurring oxygen-containing heterocyclic compounds containing dibenzo-γ-pyrone rings.[1] They occur in two major plant families, Guttiferae and Gentianaceae, and also in some families of fungi and lichens.[2,3] Natural derivatives can be hydroxylated, methoxylated or prenylated, among other possibilities; the parent compound xanthone itself is not known as a natural product.[3,4] The presence of aryl groups on the xanthone core has only been reported for a few synthetic derivatives, and as far as we know the literature had never presented the synthesis of xanthones featuring 2,3-diaryl moieties before our work.[5,6] Over the last decades these substances have been extensively studied not only because they participate in several biological functions but also as a consequence of their remarkable antifungal,[7–9] anti-inflammatory,[10,11] antimalarial[ 12–14] and antitumour activities,[15,16] and even as promising antioxidant agents.[17–19] Structure–activity stud- [a] Department of Vegetal Production and Technology, Escola Superior Agrária de Bragança, 5301-855 Bragança, Portugal Fax: +351-273-325405 E-mail: clems@ipb.pt [b] Department of Chemistry & QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal Fax: +351-234-370084 E-mail: artur.silva@ua.pt © 2009 Wiley-VCH Verlag GmbH 2642 & Co. KGaA, Weinheim Eur. J. Org. Chem. 2009, 2642–2660 bromo-2-styryl-4H-chromen-4-ones and styrenes, followed by electrocyclisation and oxidation processes. The 2,3-diaryl- 3,4-dihydro-9H-xanthene-9-one intermediates were also isolated under these conditions, and so when 5-methoxy-2-styryl- 4H-chromen-4-ones were used as starting materials the 1-hydroxy-6,7-diaryl-9H-xanthene-9-ones were also observed. The second method is a general one, because it allowed the synthesis of a great number of 2,3-diaryl-9Hxanthen- 9-ones with several substitution patterns, whereas the first one is limited to certain derivatives. The last step in the synthesis of hydroxylated 2,3-diaryl-9H-xanthen-9-ones was the cleavage of the hydroxy protecting groups with boron tribromide. The structures and stereochemistry of all new compounds were established by NMR studies. |
publishDate |
2009 |
dc.date.none.fl_str_mv |
2009 2009-01-01T00:00:00Z 2011-02-01T10:31:52Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10198/3221 |
url |
http://hdl.handle.net/10198/3221 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Santos, Clementina; Silva, Artur; Cavaleiro, José (2009). Efficient syntheses of new polyhydroxylated 2,3-diaryl-9h-xanthen-9-ones. European Journal of Organic Chemistry. ISSN 1434-193X. 16, p. 2642-2660 1434-193X 10.1002/ejoc.200900026 |
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info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Wiley |
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Wiley |
dc.source.none.fl_str_mv |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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