A three-component cascade reaction of salicylaldehyde, malononitrile/cyanoacetate and nitromethane catalysed by chiral tertiary amino-thioureas was developed, which leads to the production of highly functionalized 2-amino-4H-chromenes in good yields with good to excellent enantioselectivities.

In this study, we reported facile and efficient synthesis of 2-amino-4H-chromenes that catalyzed by polystyrene-supported 1-methylimidazolium tetrachloroferrateas. The synthesis proceeds with various aldehydes under mild conditions and afford the target products with good to high yields.

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 betw...

A series of eighteen novel 2-[(4-amino-5pyridin-3-yl-4H-1,2,4-triazol-3-yl)thio]-N-(substituted phenyl) propanamides 3(a-i) and 2-[(4-amino-5-phenyl-4H-1,2,4-triazol-3-yl) thio]-N-(substituted phenyl) propanamides 5(a-i) were synthesized by reacting 4-amino-5-pyridin-3-yl-4H-1,2,4-triazole-3-thiol (2) and 4-amino-5-phenyl-4H1,2,4-triazole-3-thiol (4) with the respective 2-chloro-N-(substituted ...

ABSTRACT A simple and efficient approach has been developed to synthesise novel functionalised 5H-chromeno[2,3-d] pyrimidines derivatives (4a-h). This entails treating 2-amino-3-cyano-4H-chromenes (3a-h) with formamidine acetate under microwave irradiations solvent-free conditions. All structures of new compounds obtained in this study were characterised by IR, MS, 1H 13C NMR analysis. Addition...

Photochromic pyrans for applications in material and life sciences were synthesized via palladium-mediated cyanation, carbonylation and Sonogashira cross-coupling starting from bromo-substituted naphthopyran 1 and benzopyrans 2a/b. A novel photoswitchable benzopyran-based omega-amino acid 6 for Fmoc-based solid-phase peptide synthesis is presented. The photochromic behaviour of the 3-cyano-subs...

Diethyl bromomalonate (2) with an equimolar amount of 2-aminophenol (1) in the presence of sodium fluoride undergoes a cyclization reaction to form 2H,4H-2-ethoxycarbonyl-3,4-dihydro-3-oxo-1,4-benzoxazine (3). Furthermore, compound 3 undergoes a condensation reaction with hydrazine hydrate in the presence of methanol to yield 2H,4H-2-hydrazinocarbonyl-3,4-dihydro-3-oxo-1,4-benzoxazine (4), whic...

this study introduces a green and efficient method for preparation of biologically-active substituted 4h-pyrans using the one-pot three-component reaction of aromatic aldehydes, dimedone and malononitrile in the presence of cobalt oxide nanoparticles. co3o4 nanoparticles were used as an efficient catalyst for the synthesis of polyhydroquinoline derivatives by the reaction of aromatic aldehydes,...