A facile, convenient, green and environmentally benign one-pot three-component synthesis of poly-functionalized 4H-pyrans and 4H-chromenes is described. A basic ionic liquid 2-(2-hydroxyethoxy)ethaneammonium formate was found to be an efficient catalyst or catalytically active solvent for the synthesis of those important classes of heterocyclic compounds.

in this research, so3h-functionalizedphthalimide (sfp) has been prepared through simple reaction of phthalimide with chlorosulfonic acid, and characterized using ft-ir, 1h nmr, 13c nmr, sem (scanning electron microscopy), mass and tg (thermal gravimetric) spectra. afterward, the solid acid has been utilized as an efficient, green, heterogeneous and recyclable catalyst for the solvent-free synth...

Abstract Regio- and stereoselective methods for the synthesis of 6′-trifluoro(trichloro)methyl substituted spiro[acenaphthylene-1,11′-chromeno[3,4-a](thia)pyrrolizidin]-2-ones spiro[acenaphthylene-1,12′-chromeno[3,4-a]indolizidin]-2-ones have been developed based on three-component reaction 3-nitro-2-trifluoro(trichloro)methyl-2H-chromenes with azomethine ylides generated in situ from acenaphth...

in this study, the synthesis of 4 h -chromenes of biological activity via a multicomponent reaction of dimedone, aromatic aldehydes and malononitrile catalyzed by glutamic acid as a catalyst was investigated. the structural features of the synthesized compounds were characterized by melting point, ir and 1 h nmr analysis. the catalyst being reported here is cheap, safe to handle and the whole p...

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.

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.

A new route to the chromene ring system has been developed which involves the reaction of an α,β-unsaturated Fischer carbene complex of chromium with a propargyl ether bearing an alkenyl group on the propargylic carbon. This transformation involves a cascade of reactions that begins with a benzannulation reaction and is followed by the formation of an o-quinone methide, and finally results in t...

A mild palladium-catalyzed ligand-controlled regioselective 1,3-arylfluorination of 2[H]-chromenes has been developed. The products with a syn-1,3 substitution pattern were obtained with high enantiomeric excess using a PyrOx ligand, wherein the utility of these pyranyl-fluorides was further demonstrated through their participation in a diastereoselective C-C bond forming reaction. Ligand depen...