Efficient synthesis of novel 9H-xanthen-9-yl derivatives of bidentate heterocyclic nucleophiles by Fe(HSO4)3 as a catalyst (original) (raw)
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Cheminform, 2009
Abstr act. Fe(HSO 4 ) 3 (FHS) was used as an efficient catalyst for the heterogeneous addition of a series of benzylic and allylic alcohols to various β-dicarbonyl compounds, which afforded moderate to excellent yields of C-alkylated products in 1,2-dichloroethane. In comparison with the previous methods, the present research surprisingly exhibited higher reaction yields without formation of any by-products which could be formed by self-condensation of alcohols. Moreover, the catalyst can be readily recovered and reused up to five times with almost maintained reactivity and yields.
Chinese Chemical Letters, 2008
Abstr act. Fe(HSO 4 ) 3 (FHS) was used as an efficient catalyst for the heterogeneous addition of a series of benzylic and allylic alcohols to various β-dicarbonyl compounds, which afforded moderate to excellent yields of C-alkylated products in 1,2-dichloroethane. In comparison with the previous methods, the present research surprisingly exhibited higher reaction yields without formation of any by-products which could be formed by self-condensation of alcohols. Moreover, the catalyst can be readily recovered and reused up to five times with almost maintained reactivity and yields.
Journal of the Brazilian Chemical Society, 2008
O hidrogenossulfato férrico tem sido utilizado como catalisador para a preparação em um único pote dos derivados de aril 14H-dibenzo[a,j]xantenos por ciclocondensação de-naftol e benzaldeídos substituídos, em condições livres de solvente e aquecimento. Este método tem a vantagem de fornecer rendimentos elevados, reações mais limpas, metodologia simples, menor tempo de reação, fácil tratamento e condições experimentais menos poluentes. Ferric hydrogensulfate as catalyst has been used for the one-pot preparation of aryl 14Hdibenzo[a,j]xanthene derivatives by cyclocondensation of-naphthol and substituted benzaldehydes under solvent-free and thermal conditions. This method has the advantages of high yields, a cleaner reaction, simple methodology, short reaction times, easy workup and greener conditions.
2013
Synthesis of xanthenediones is a continuing hot top ic because these moieties are privileged pharmacophores as well as valuable reactive interme diates for both synthetic and medicinal chemists . Furthermore, these compounds can be used as dyes , in laser technologies , and as pH sensitive fluorescent materials for visualization of biomolec ules. In addition, substituted xanthenes are structural key-units in several natural products . Many procedures exist for the synthesis of 1,8-diox o-xanthenes involving InCl 3/P2O5 , [Hbim]BF4/ultrasound , silica-bonded S-sulfonic acid , PMA.SiO2 , p-dodecylbenzenesulfonic acid , amberlyst-15, SmCl3 , Fe3O4 nanoparticles , PEG-6000 , molecular iodine , cat. H2SO4 , ZrOCl2·8H2O , p-TSA, [bmim]HSO4 , Fe(HSO4)3 20 , diammonium hydrogen phosphate , etc. However, many of these methods include strong acidi c reaction conditions, low yields, long reaction times, high temperatures or they are dedicated only to the application of ar matic aldehydes, use ...
2016
Cobalt hydrogensulfate is an efficient catalyst for the condensation of β-naphthol, aromatic aldehydes and 5,5-dimethyl-1,3cyclohexanedione at 120 °C to afford 9,9-dimethyl-12-phenyl-8,10,11,12-tetrahydro-9-H-benzo[a]xanthen-11-one derivatives in high yields. Also, polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of cobalt hydrogensulphate under solvent-free conditions. Simple and convenient procedure, high conversion, reusability of catalyst, easy purification and short reaction time are the advantageous features of this method.