Cerous <i>p</i>-Toluenesulfonate as an Efficient and Recyclable Catalyst for the Synthesis of <i>N</i>1-Substituted-4-aryl-3,4-dihydropyrimidin-2(1<i>H</i>)-ones
作者:Min Wang、Hongxu Jiang、Shun Zhang、He Pan
DOI:10.1080/00304948.2018.1525672
日期:2018.9.3
agents and a1aantagonists. Since the first straightforward synthetic method for DHPMs was reported by Biginelli in 1893, many improved protocols were developed. Not only new catalysts and reaction conditions were explored but also some novel reactive species were formed. The scope of the Biginellireaction extended to various building blocks, so a large number of multifunctional pyrimidine derivatives with
Solvent-Free Ball-Milling Biginelli Reaction by Subcomponent Synthesis
作者:Prasit Kumar Sahoo、Anima Bose、Prasenjit Mal
DOI:10.1002/ejoc.201501039
日期:2015.11
here an understanding of systems chemistry on small molecules through covalent mechanochemistry. As a proof-of-concept, the multicomponent Biginellireaction by subcomponentsynthesis was considered as a model system. Reactions were performed under solvent-free, metal-free, mechanochemical (ball milling) and ambient laboratory conditions. Br+-catalyzed oxidation of benzyl alcohols led to the product
Biginelli reactions were well catalyzed on mesoporous silica MCM-41 (M41) whose activity was much greater than that of amorphous silica. Octane was the most suitable among 6 kinds of solvents examined. The addition of metal ions on M41 enhanced the catalytic activity in the order Al > Ti > Fe = In. Al-planted M41s with Si/Al ratios of 45–35 showed the highest catalytic activity and could be used repeatedly though a small loss of the activity was observed. The catalysis could widely be applied to obtain various substituted dihydropyrimidinones (DHPMs) with high yields, some of which were very difficult to prepare until now. In addition, Biginelli reactions were combined with formyl C–H insertion reactions of diazoester on mesoporous silica; that is, a tandem one-pot four-component DHPM synthesis was attempted. Acetaldehyde, ethyl diazoacetate, p-tolualdehyde, and urea could be condensed and the corresponding DHPM derivative was obtained with 50% yield on Al-planted M41.