Silica-Supported Ionic Liquid Si-[SbSipim][PF₆]: An Efficient Catalyst for the Synthesis of 3,4-Dihydropyrimidine-2-(1H)-ones

Brønsted Acidic 1-Ethyl-1,2,4-Trizolium Phenylsulfonate as Catalyst for Biginelli Reaction

“…In Biginelli reaction, chemists used number of catalyst like metal salts such as LiBr, FeCl3/Si(OEt)4, Cu(OTf)2, CeCl3 [11][12][13][14][15][16][17][18]. Many types of zeolite catalyzed and inorganic acid catalyzed have been reported for the synthesis of dihydropyrimidinones/ thiones [19][20][21]. However, the above catalyst used in Biginelli reaction protocols are coupled with certain limitations such as less biodegradability of the catalyst, costly reagents for the synthesis of catalyst, drastic reaction conditions and generation of chemical wastages.…”

Synthesis of 1-alkyl triazolium triflate room temperature ionic liquids and their catalytic studies in multi-component Biginelli reaction

“…Those methods involved use of a number of metal salts, such as Li, 6 Fe, [7][8][9][10] Cu, 11,12 Ce, 13 Zr, 14 In, 16 Bi, 17 Yb, 18 La, 19 Al, 20,21 Sn, 22 Mn, 23 Ti 24 and nanomaterials of Fe 3 O 4 . 25 Several zeolite catalyzed [26][27][28] and non-metal acid catalyzed [29][30][31][32] syntheses of dihydropyrimidinone have also been reported. However, some of these * For correspondence procedures are associated with certain limitations such as use of metal catalysts, expensive reagents, and drastic reaction conditions, use of microwave or ultrasonication which often resulted in unsatisfactory yields of product.…”