MÉTODOS AMBIENTALMENTE AMIGÁVEIS PARA A IODAÇÃO REGIOSSELETIVA DA 3,7,3’,4’-TETRAMETOXI-QUERCETINA
Halogenated compounds are valuable substrates for the field of organic synthesis and more specifically as reagents for coupling reactions. Environmental friendly procedures for regioselective iodination is the aim of this study, using four different methods previously described in the literature, th...
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Química
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| Series: | Química Nova |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422018000500577&lng=en&tlng=en |
| _version_ | 1818180585492840448 |
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| author | Ingrid T. L. Ramos Telma M. G. da Silva Tania M. S. da Silva Celso A. Camara |
| author_facet | Ingrid T. L. Ramos Telma M. G. da Silva Tania M. S. da Silva Celso A. Camara |
| author_sort | Ingrid T. L. Ramos |
| collection | DOAJ |
| description | Halogenated compounds are valuable substrates for the field of organic synthesis and more specifically as reagents for coupling reactions. Environmental friendly procedures for regioselective iodination is the aim of this study, using four different methods previously described in the literature, that embrace green chemistry concepts, to obtain the 6- and 8-iodo-isomers of 3,7,3’,4’-tetramethoxy-quercetin. As traditional column chromatography does not resolve the mixture of isomers, the regioselectivity for iodination was quantified by use of HPLC. The use of a protic polar solvent improves selectivity for formation of the 8-iodo- isomers (tipically, I2, LiOH, MeOH, 3 h, 54% yield), while the use of a polar aprotic solvent or in the absence of a solvent favors formation of the 6-iodo- isomer (typically, I2, K2CO3, without solvent, 5 min, 60% yield). Twenty-one reaction procedures were investigated, five of which selectively gave the 6,8-diiodo-derivative. To the best of our knowledge, selective methods for the synthesis of this compound have not been described in the literature. The best condition was the neat reaction with N-iodo-succinimide with 68% yield in just a few minutes. All product yields are after column chromatography using silica gel, and characterized by usual methods, including 1H-NMR, 13C-NMR, IR and MS-TOF. |
| first_indexed | 2024-12-11T21:22:06Z |
| format | Article |
| id | doaj.art-f98fd65106da4a9fb297d43511aec46c |
| institution | Directory Open Access Journal |
| issn | 1678-7064 |
| language | English |
| last_indexed | 2024-12-11T21:22:06Z |
| publisher | Sociedade Brasileira de Química |
| record_format | Article |
| series | Química Nova |
| spelling | doaj.art-f98fd65106da4a9fb297d43511aec46c2022-12-22T00:50:26ZengSociedade Brasileira de QuímicaQuímica Nova1678-706441557758010.21577/0100-4042.20170205S0100-40422018000500577MÉTODOS AMBIENTALMENTE AMIGÁVEIS PARA A IODAÇÃO REGIOSSELETIVA DA 3,7,3’,4’-TETRAMETOXI-QUERCETINAIngrid T. L. RamosTelma M. G. da SilvaTania M. S. da SilvaCelso A. CamaraHalogenated compounds are valuable substrates for the field of organic synthesis and more specifically as reagents for coupling reactions. Environmental friendly procedures for regioselective iodination is the aim of this study, using four different methods previously described in the literature, that embrace green chemistry concepts, to obtain the 6- and 8-iodo-isomers of 3,7,3’,4’-tetramethoxy-quercetin. As traditional column chromatography does not resolve the mixture of isomers, the regioselectivity for iodination was quantified by use of HPLC. The use of a protic polar solvent improves selectivity for formation of the 8-iodo- isomers (tipically, I2, LiOH, MeOH, 3 h, 54% yield), while the use of a polar aprotic solvent or in the absence of a solvent favors formation of the 6-iodo- isomer (typically, I2, K2CO3, without solvent, 5 min, 60% yield). Twenty-one reaction procedures were investigated, five of which selectively gave the 6,8-diiodo-derivative. To the best of our knowledge, selective methods for the synthesis of this compound have not been described in the literature. The best condition was the neat reaction with N-iodo-succinimide with 68% yield in just a few minutes. All product yields are after column chromatography using silica gel, and characterized by usual methods, including 1H-NMR, 13C-NMR, IR and MS-TOF.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422018000500577&lng=en&tlng=enflavonoidsquercetinregioselectiveiodinationeco-friendly |
| spellingShingle | Ingrid T. L. Ramos Telma M. G. da Silva Tania M. S. da Silva Celso A. Camara MÉTODOS AMBIENTALMENTE AMIGÁVEIS PARA A IODAÇÃO REGIOSSELETIVA DA 3,7,3’,4’-TETRAMETOXI-QUERCETINA Química Nova flavonoids quercetin regioselective iodination eco-friendly |
| title | MÉTODOS AMBIENTALMENTE AMIGÁVEIS PARA A IODAÇÃO REGIOSSELETIVA DA 3,7,3’,4’-TETRAMETOXI-QUERCETINA |
| title_full | MÉTODOS AMBIENTALMENTE AMIGÁVEIS PARA A IODAÇÃO REGIOSSELETIVA DA 3,7,3’,4’-TETRAMETOXI-QUERCETINA |
| title_fullStr | MÉTODOS AMBIENTALMENTE AMIGÁVEIS PARA A IODAÇÃO REGIOSSELETIVA DA 3,7,3’,4’-TETRAMETOXI-QUERCETINA |
| title_full_unstemmed | MÉTODOS AMBIENTALMENTE AMIGÁVEIS PARA A IODAÇÃO REGIOSSELETIVA DA 3,7,3’,4’-TETRAMETOXI-QUERCETINA |
| title_short | MÉTODOS AMBIENTALMENTE AMIGÁVEIS PARA A IODAÇÃO REGIOSSELETIVA DA 3,7,3’,4’-TETRAMETOXI-QUERCETINA |
| title_sort | metodos ambientalmente amigaveis para a iodacao regiosseletiva da 3 7 3 4 tetrametoxi quercetina |
| topic | flavonoids quercetin regioselective iodination eco-friendly |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422018000500577&lng=en&tlng=en |
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