Solvent‐Free Microwave‐Assisted Multicomponent Synthesis of 4 H ‐Chromenes Using Fe 3 O 4 ‐Based Hydrotalcites as Bifunctional Catalysts

NOPE, ELIANA; SATHICQ, ÁNGEL G.; MARTÍNEZ, JOSÉ J.; ROJAS, HUGO; MACÍAS, MARIO A.; CASTILLO, JUAN CARLOS; ROMANELLI, GUSTAVO

ChemistrySelect

Royal Society of Chemistry

Año: 2022 vol. 7 p. 1 - 10

2365-6549

Magnetic Fe3O4-based hydrotalcites were used as bifunctionalcatalysts for the microwave-assisted solvent-free synthesis of4H-chromene derivatives by a three-component reaction from(hetero)aromatic aldehydes, malononitrile, and naphthol deriv-atives. Structures of 4H-chromenes 4d and 4g were studiedand confirmed by single-crystal X-ray diffraction analysis. Theheterogeneous catalysts were synthesized by the co-precipita-tion method incorporating divalent metal cations such as Ni2+or Co2+ in LDH-Mg. This multicomponent protocol allows thesynthesis of diverse 4H-chromenes in 88?95% yields, reducedreaction time, high atom economy, broad substrate scope, andoperational simplicity. The reusability of the catalyst up to fiverecycles without appreciable loss of its catalytic activity, makethe present protocol sustainable and advantageous comparedto conventional methods.