Preparation and characterization of MCM-۴۱@Schiff-base@La as arecyclable heterogeneous nanocatalyst for the synthesis oftetrahydrobenzo[b]pyran derivatives and oxidation of sulfides

In this paper, MCM-۴۱@Schiff-base@La as a novel, green, heterogeneous, and extremelyefficient nanocatalyst was successfully synthesized by the immobilization of La complex onMCM-۴۱ modified mesoporous silica. The prepared catalyst was characterized by TGA, FT-IR,ICP, BET, SEM and EDX techniques. The synthesized nanoparticle was sused as a recyclabilitycatalyst for synthesis of tetrahydrobenzo[b]pyran and sulfoxide derivatives.Tetrahydrobenzo[b]pyran derivatives are an important class of heterocyclic compounds with manyapplications. These compounds are synthesized from the condensation of aromatic aldehydes,dimedone and malononitrile in the presence of various catalysts. ۴H-pyran derivatives havepharmacological and biological activities, such as anticancer, antifungal, antibacterial, antioxidant,anticoagulant, antianaphylactic, spasmolytic, antiviral, antileishmanial, antiallergenic and diuretic[۱, ۲]. Beside, sulfoxides play as therapeutic agents such as anti-hypertensive, anti-fungal, antiulcer,anti-bacterial, anti-atherosclerotic, and psychoactive. Also, sulfoxides are goodintermediates in the synthesis of some vitamins and drugs [۳,۴].

Keywords:

Mesoporous KIT-۶ , nanocatalyst , lanthanum , tetrahydrobenzo[b]pyrans , sulfoxides