Solvent-free synthesis of flavanones over aminopropyl-functionalized SBA-15

Flavanone was synthesized through the Claisen–Schmidt condensation between benzaldehyde and acetophenone and subsequent intramolecular Michael addition over aminopropyl-functionalized SBA-15 materials. The catalysts with well-ordered hexagonally arranged mesopores were synthesized by one-pot co-condensation of tetraethoxysilane and aminopropyltriethoxysilane using amphiphilic block copolymer as the template under acidic condition. The results showed that the catalysts had good activities and very high selectivities to flavanone in solvent-free condition, while the use of organic solvents decreased the catalytic activities and flavanone selectivities. The influence of substituents in the aromatic rings of benzaldehyde and 2′-hydroxyacetophenone was also investigated under the solvent-free condition.