A green synthesis of 3,4-dihydropyrimidine-2(1H)-one/thione derivatives using nanosilica-supported tin(II) chloride as a heterogeneous nanocatalyst

12‐Tungstosilicic Acid H4[W12SiO40] Over Natural Bentonite as a Heterogeneous Catalyst for the Synthesis of 3,4‐dihydropyrimidin‐2(1H)‐Ones

“…Similar finding was also reported by kolvari et al where they showed that amount of catalyst (n‐ZrSA) increased from 5 mol % to 10 mol %, yield of corresponding DHPM increased from 86 % to 98 % and further enhanced catalyst loading from 10 mol % to 15 mol % led to decline in product efficiency from 98 % to 78 %.The model reaction carried out with raw bentonite resulted in a 20 % efficiency of the product at 48 h(entry 12, Table ). It has been reported that this reaction is sensitive to solvents . Therefore reaction carried out in different solvents using 30 % TSA/bent catalyst in order to investigate the role of solvents.…”

A Brønsted acidic ionic liquid anchored to magnetite nanoparticles as a novel recoverable heterogeneous catalyst for the Biginelli reaction

“…12 The synthesis of 3,4-dihydropyrimidinone compounds can be performed under different conditions, including under strongly acidic conditions in a protic solvent. [13][14][15][16] It has traditionally been catalysed using strong Brønsted acids; Lewis acids; [17][18][19][20][21] homogeneous acid catalysts, such as polyphosphate esters, 22 ZnCl 2 , or CuCl 2 ; 23 heterogeneous acid catalysts, like Al-MCM-41 or FeCl 3 embedded in Al-MCM-41; 24 nanocomposites; 25,26 nanoparticles; 27 magnetic nanoparticles; 28 metal oxides; and enzymes. Also, this reaction can be modied using microwave irradiation, 29,30 ultrasound irradiation, 31 ionic liquids, [32][33][34] and organocatalysis, 35 or using a combination of these.…”

Fe(III)/Bentonite as a Heterogeneous Catalyst for the Synthesis of 3,4‐dihydropyrimidin‐2‐(1H)‐ones

“…Various Lewis acids are supported over different kind of solid support for this reaction. These are FeCl 3 @nanopore silica, Lewis acids (ZnCl 2 ,AlCl 3 ,GaCl 3 ,InCl 3 and FeCl 3 ) @MCM‐41 & montmorrionolite K 10 clay, ZnCl 2 over silica, Cu@PMO‐IL, MoO 3 @Al 2 O 3 , HBF 4 ‐SiO 2 , SbCl 3 @Al 2 O 3 , LaCl 3 ‐graphite, Mo/γ‐Al 2 O 3 , CuCl 2 ‐SiO 2 , SnCl 4 & TiCl 4 @SiO 2 , FeCl 3 @Al‐MCM‐41, FeCl 3 @PANI, Nafion‐Ga, Yttria‐Zirconia, ZrO 2 ‐pillared clay, Ce@MCM‐41, Ps‐AlCl 3 , metalsalts@NaY, SnCl 2 @nanoSiO 2 , Mg/Fe hydrotalcite, ZnCl 2 , CuCl 2 , NiCl 2 , and CoCl 2 doped hydroxyapatite, ZnCl 2 , CuCl 2 and NiCl 2 doped fluorapatite, SOCl 2 @ silica gel and recently work on HClO 4 ‐Al 2 O 3 were devised for Biginelli reaction [31–55] . These reported catalyst exhibited very good yield towards DHPMS/DHPMTHs with good reusability.…”