HClO4–SiO2 catalyzed stereoselective synthesis of β-amino ketones via a direct Mannich-type reaction

An Eco-Friendly Protocol for Synthesis of β- aminoketones via Mannich Reaction Using Citric Acid: A Biodegradable Catalyst

“…β-amino carbonyl derivatives are found in a number of biologically active natural products [5]. The reported Mannich reactions have been catalyzed by various Lewis or Brønsted acid catalysts such as silica-supported AlCl 3 [6], CeCl 3 .7H 2 0 [7], NbCl 5 [8], BiCl 3 [9], CAN [10], HClO 4 -SiO 2 [11], Bi(OTf) 3 [12], Zn(OTf) 2 [13], ionic liquid [14][15][16][17], sulphamic acid [18][19][20], Fe(Cp) 2 PF 6 [21], Cu-nanoparticles [22], [RE(PFO) 3 ] [23], silica based tin(II) catalyst [24], PEG-SO 3 H [25] ZSM-5-SO 3 H [26], carbon based solid acid [27], polyaniline/SiO 2 [28], lipase [29], saccharose [30], heteroplyacid salts [31]. However, most of the reported methods for the Mannich reaction suffer from drawbacks such as long reaction times and harsh reaction conditions, toxicity, and difficulty in product separation, which limit its use in the synthesis of complex molecules.…”

One Pot Synthesis of Multiaryl-Substitutedβ-Amino Ketone Compo- unds Catalyzed by Silica-Supported Rare Earth Terbium Chloride

“…近几年, 对支载、负载型催化剂研究越来越受重视, 文 献 报 道 , SiO 2 -OAlCl 2 [19] , H 2 SO 4 -SiO 2 [20] 和 HClO 4 -SiO 2 [21] 等已经作为一种新型催化剂应用到合成 β-氨基 …”

Assessment of the Catalytic Activities of Novel Brönsted Acidic Ionic Liquid Catalysts

“…One pot three component strategy can be adopted to prepare such compounds. A variety of catalysts, Zn(Otf) 2 [29,30] [34] and HClO 4 -SiO 2 [35] have been reported for this reaction. However, these catalysts have several drawbacks, such as long reaction time, use of costly and non-recoverable catalysts, and requirement of special effort for catalyst preparation.…”