Immobilization of tris hydroxyaminomethyl methane on hercynite MNPsas a magnetically recoverable organocatalyst in the synthesis oftetrahydrobenzo[b]pyran derivatives

Recently, heterogeneous catalysts have been used in organic reactions and modern organicsynthesis [۱,۲]. In this regard, hercynite magnetic nanoparticles have high density of hydroxylgroups on its surface, which could be available for immobilization of various catalysts [۳].Therefore, hercynite magnetic nanoparticles have attracted great attention, especially in thesynthesis of heterogeneous catalysts, due to their feasible recovering and reusing by an externalmagnet [۴]. More addition, hercynite nanoparticles is composed from Al, O and Fe, which haveseveral unique properties such as easy availability, high surface area, non-toxicity, and low cost[۳,۴]. In this work, hercynite magnetic nanoparticles were synthesized and its surface was coatedby a silica layer. Then its surface was modified by ۳-choloropropyltrimtoxysilane. Finally,tris(hydroxymethyl)amino methane was immobilized on the surface of modified hercynitenanoparticles (THMAM@SiO۲@hercynite NPs). In the next step, THMAM@SiO۲@hercyniteNPs was characterized by by SEM, EDS, WDX, TGA, XRD, VSM, and FT-IR techniques. Thecatalytic activity of tetrahydrobenzo[b]pyran NPs was studied in the synthesis oftetrahydrobenzo[b]pyran derivatives.

Keywords:

Hercynite nanoparticles , magnetic nanoparticles , tris hydroxyaminomethylmethane , tetrahydrobenzo[b]pyran , recoverable organocatalyst