Catalytic activity of AlHMS was investigated as a cheap heterogeneous reusable catalyst in some multi-component reactions for the synthesis of various chromenes. Three-component reaction of 2-hydroxy-naphtoquinone with an aromatic aldehyde and dimedone or barbituric acid in H2O under reflux conditions was performed using AlHMS in relatively good yields. The approach was more extended using psue...

decatungstodivanadogermanic acid (h6gew10v2o40.22h2o) was used as a green heterogeneous catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1h)-ones from one-pot three-component cyclocondensation reaction of a β-ketoester, an aldehyde and urea/thiourea under solvent-free conditions is reported. this method provides an efficient and much improved modification of the original biginelli reaction...

A new and improved protocol for the synthesis, in good to excellent yields, of acridine-1,8(2H,5H)-diones is described, involving a one-pot, three component reaction of dimedone, arylglyoxals, and ammonium acetate in water under microwave irradiation.  

Microwave-assisted three component cyclocondensation reactions of aldehydes, amides and dienophiles in the presence of acetic anhydride and para-toluenesulfonic acid as a catalyst to afford the highly substituted cyclohexene derivatives, in relatively good yields after several minutes are reported.

A simple and efficient one-pot, three-component Strecker reaction of protected amino acids, aromatic aldehydes, and trimethylsilyl cyanide has been developed for the synthesis of chiral α-amino nitriles. The reaction was carried out in the presence of catalytic amount of phosphotungstic acid (H3[P(W3O10)4]) as an environmentally friendly cata...

A facile and efficient one-pot, multicomponent synthesis of 4H-chromenes is reported, through the reaction of arylglyoxalmonohydrates with 1,3-diketones and malononitrile in eTEMPthanol in the presence of L-proline as a catalyst.