In this paper, MCM-41@Schiff-base@La as a novel, green, heterogeneous, and extremely efficient nanocatalyst was successfully synthesized by the immobilization of La complex on MCM-41 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 recyclability catalyst for synthesis of tetrahydrobenzo[b]pyran and sulfoxide derivatives. Tetrahydrobenzo[b]pyran derivatives are an important class of heterocyclic compounds with many applications. These compounds are synthesized from the condensation of aromatic aldehydes, dimedone and malononitrile in the presence of various catalysts. 4H-pyran derivatives have pharmacological and biological activities, such as anticancer, antifungal, antibacterial, antioxidant, anticoagulant, antianaphylactic, spasmolytic, antiviral, antileishmanial, antiallergenic and diuretic [1, 2]. Beside, sulfoxides play as therapeutic agents such as anti-hypertensive, anti-fungal, anti-ulcer, anti-bacterial, anti-atherosclerotic, and psychoactive. Also, sulfoxides are good intermediates in the synthesis of some vitamins and drugs [3, 4].
