One-pot synthesis of dihydropyrimidines via eco-friendly phosphorus derivatives catalysis

Unprecedented linear products by a mechanochemically activated Biginelli reaction using lawsone

“…of 4-chlorobenzaldehyde under the same reaction conditions (entry 3, Table 1) expectedly afforded the Michael adduct 8 . Under refluxing conditions in EtOH and catalysed by 10 mol% hypophosphorous acid 39 the three-component reaction led to a mixture which upon purification afforded 8 in 15% yield and compound 7 in 35% yield (entry 4, Table 1). Again, no Biginelli-cyclized compound DHPM was observed.…”

The untold story of starch as a catalyst for organic reactions

“…165,166 These structures can be found in several candidate drugs. 167 To facilitate the preparation of these important heterocyclic compounds, Foroughifar's research group introduced magnetic starch support loaded with aspartic acid (Scheme 48). 168 To prepare the mentioned catalyst, MnFeCaFe 2 O 4 @starch@aspartic acid, first, they prepared a MnFeCaFe 2 O 4 as the core of the catalyst through the coprecipitation of related salts.…”

Advances in Biginelli reaction: A comprehensive review

“…Benhida et al reported a cost-effective method for the synthesis of dihydropyrimidines via Biginelli reaction using hydrophosphorous acid as a catalyst. 33 Model substrates used in the reaction included aldehyde, β-dicarbonyl derivative, and urea derivative, and the reaction was carried out under optimal conditions with ethanol functioning as the solvent along with hydrophosphorous acid acting as the catalyst, employing them for 6 h at 80 C and obtained a high yield of 96% (Scheme 12). By using electron-donating groups such as 4-methoxy and 3-hydroxy and electron-withdrawing groups like nitro and cyano, on the aromatic ring of the aldehyde, a high yield of 92% to 98% for electrondonating groups and 82% to 97% for electronwithdrawing groups was achieved.…”

“…Benhida et al reported a cost‐effective method for the synthesis of dihydropyrimidines via Biginelli reaction using hydrophosphorous acid as a catalyst 33 . Model substrates used in the reaction included aldehyde, β‐dicarbonyl derivative, and urea derivative, and the reaction was carried out under optimal conditions with ethanol functioning as the solvent along with hydrophosphorous acid acting as the catalyst, employing them for 6 h at 80°C and obtained a high yield of 96% (Scheme 12).…”