Silica supported-double metal cyanides (DMCs): A green and highly efficient catalytic protocol for isomerisation of 2¡ä-hydroxychalcones to flavanones

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• 作者：Naseem Ahmed ; ^{nasemfcy@iitr.ernet.in} ; ^{naseem2008@gmail.com} ; Naveen Kumar Konduru ; Praveen ; Anand Kumar ; Kamaluddin
• 关键词：Silica supported-double metal cyanide (DMC) catalyst ; Isomerisation ; 2&prime ; -Hydroxychalcones ; Flavanones
• 刊名：Journal of Molecular Catalysis A: Chemical
• 出版年：2013
• 出版时间：July, 2013
• 年：2013
• 卷：373
• 期：Complete
• 页码：135-141
• 全文大小：1221 K

文摘

Four different double metal cyanides (NiHCFe, CrHCFe, MnHCFe and ZnHCFe) were synthesized, followed by adsorbed on silica gel and used as Lewis acid catalyst in the isomerisation of substituted 2¡ä-hydroxychalcones to flavanones under solvent-free (dry) condition. Optimization of the reaction condition, temperature effects, DMC catalysts loading and re-useable catalytic activity were further studied during the reaction. Among these catalysts, NiHCFe at 35 mol % loading gave excellent yield (90 % ) at 100 ¡ãC temperature in 1.15 h. Catalyst (NiHCFe) easily recovered and re-used six times without much loss of its catalytic activity which gave 80-85 % product yields each time. However, these DMCs were failed to give product in the solution phase even prolonging the reaction time at reflux temperature. Similarly, isomerization of substituted 2¡ä-aminochalcones gave 2-5 % yields either in solution phase or under solvent-free condition.