2-Amino-3-cyano-4H-chromenes show great potential as novel anticancer agents. Here we report a quinine-catalyzed highly enantioselective formal 4 + 2 cycloaddition of ortho-quinone methides and malononitrile, providing a unique approach to 4-arylvinyl, 4-aryl and 4-vinyl 2-amino-3-cyano-4H-chromenes with excellent yields and enantioselectivities. Moreover, this reaction can be performed in up t...

a simple, efficient, and high yielding one-pot protocol has been developed for the synthesis of 4h-benzo[b]pyrans scaffolds installing a three-component tandem knoevenagel-cyclocondensation reaction of an aldehyde, malononitrile and dimedone using guanidinium chloride as polyfunctional organocatalyst under solvent-free conditions in high to excellent yields. various aromatic aldehydes were util...

The aminomethylation of hydroxylated isoflavones with 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, and 5-amino-1-pentanol in the presence of excess formaldehyde led principally to 9-(2-hydroalkyl)-9,10-dihydro-4H,8H-chromeno[8,7-e][1,3]-oxazin-4-ones 4 and/or the tautomeric 7-hydroxy-8-(1,3-oxazepan-3-ylmethyl)-4H-chromen-4-ones 5. The ratio of these tautomers was dependent on solvent...

Silica-bonded n-propyltriethylene-tetramine (SBNPTT) was found as an efficient solid base for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromenes. Chromene derivatives were obtained via the three-component condensation reaction of aromatic aldehydes, malononitrile, and dimedone at 80 oC under solvent-free conditions. The heterogeneous solid base showed much the same efficiency when u...

A simple, efficient, and high yielding one-pot protocol has been developed for the synthesis of 4H-benzo[b]pyrans scaffolds installing a three-component tandem Knoevenagel-cyclocondensation reaction of an aldehyde, malononitrile and dimedone using guanidinium chloride as polyfunctional organocatalyst under solvent-free conditions in high to excellent yields. Various aromatic aldehydes were util...

nanoporous sodium montmorillonite clay (na+-mmt) was used as a support for the immobilization of 1-methyl-3-(trimethoxysilylpropyl)-imidazolium hydrogen sulfate (na+-mmt-[pmim]hso4). this catalyst showed excellent catalytic activity for the preparation of 2-amino-3-cyano-5-oxo-5,6,7,8-tetrahydro-4h-benzopyrans via three-component reactions between aldehydes, dimedone and malononitrile. the proc...

Diazotization of 3-amino-2-cMoro pyridine (3) in the presence of dithizone (5) gave dphenyl-2-phenylazo-4H-pyrid[o3 ,2-e] [1,3,4] thiadiazine (6). Reaction of 2- chloro-3-nitropyridine (2, G=H) with (5) dfordd 4-phenyl -2-phenylazo -4Hpyrido [2,3-el [1,3,4] thiadiazine (7). Reduction of the latter with H gas in the presence of Raney nickel gave the corresponding amino derivative (12). One ...

In the present study, new Schiff's base derivatives: (Z)-4-amino-5-(2-(3- fluorobenzylidene)hydrazinyl)-4H-1,2,4-triazole-3-thiol (Y1), (Z)-3-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y2), (Z)-2-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y3) and 3-((Z)-(2-(4- (((E)-3-hydroxybenzylidene)amino)-5-mercapto-4H-1,2,4-triazol-3-yl)hydrazono)m...