Sulfonated Organic Heteropolyacid Salts: Recyclable Green Solid Catalysts for the Highly Efficient and Green Synthesis of Bis(indolyl)methanes in Water
Sulfonated Organic Heteropolyacid Salts: Recyclable Green Solid Catalysts for the Highly Efficient and Green Synthesis of Bis(indolyl)methanes in Water
作者:Seyed M. Vahdat、Samad Khaksar、Saeed Baghery
DOI:10.2174/157017812800221690
日期:2012.2.1
In the present study, we introduce two nonconventional ionic liquids [MIMPS]3PW12O40 (a) and [TEAPS]3PW12O40 (b) as green solid acid catalysts for the efficient synthesis of bis(indolyl)methanes. The reaction of indole with aldehydes or ketones in water afforded the corresponding bis(indolyl)methanes in excellent yields. This reaction has been carried out in the presence of 1 mol% of catalysts at room temperature. The reusability of the catalysts was demonstrated by a six-run test. Additionally, the catalysts pose several advantages including mild reaction conditions, cleaner reactions and shorter reaction times.
Highly Efficient Povidone-Phosphotungstic Acid Catalyst for the Tandem Acetalization of Aldehydes to Bis- and Tris(indolyl)methanes
作者:Sumit B. Kamble、Rameshwar K. Swami、Sachin S. Sakate、Chandrashekhar V. Rode
DOI:10.1002/cplu.201300248
日期:2013.11
A novel, nonleachable hybrid of heteropoly acid and polyvinylpyrrolidone (or povidone) catalyzes the acetalization of aldehydes in methanol at roomtemperature followed by reaction with indole to give bis(indolyl)methanes (BIMs) and tris(indolyl)methanes (TIMs) in quantitative yields (90-97 %). The catalyst was shown by pyridine FTIR spectroscopy to possess Brønsted acidity, and the hybrid formation
新型,不可浸出的杂多酸和聚乙烯吡咯烷酮(或聚维酮)的杂物在室温下催化甲醇中醛的缩醛化,然后与吲哚反应生成定量的双(吲哚基)甲烷(BIM)和三(吲哚基)甲烷(TIM)收率(90-97%)。吡啶FTIR光谱表明该催化剂具有布朗斯台德酸度,并且通过XRD和31 P NMR研究证实了杂化物的形成。用几种类型的羰基和吲哚底物建立了吲哚的Friedel-Crafts烷基化以及BIM和TIM的串联合成,以定量得到相应的产物。该催化剂有效地再循环了三个连续的运行而没有失去其原始活性。