Novel and sustainable synthesis of tetrahydrobenzo[b]pyrans using magnetic zinc ferrites modified SBA-15 supported ionic liquids as efficient and reusable catalysts

A series of magnetic zinc ferrites modified SBA-15 supported ionic liquids has been synthesized and evaluated as effective catalysts for the one-pot multi-component reaction of equimolar amounts of aldehydes, malononitrile and 1,3-cyclohexanedione in aqueous medium. Most of these magnetic supported ionic liquids showed good results in the reaction, especially the catalysts Zn(0.2)Ee(2.8)O(4)@SBA-15(0.5)@CH3COO(0.2) and Zn0.2Fe2.8O4@SBA-15(0.)(5)@ILCH3COO(0.3). The most active and suitable catalyst was the catalyst Zn0.2Fe2.8O4@SBA-15(0.)(5)@CH3COO(0.2), which containing synergestic zinc ferrites and ionic liquid active sites effect and can efficiently and selectively produce the corresponding tetrahydrobenzo[b]pyrans in high to excellent yields at room temperature. Moreover, the catalyst exhibited excellent stability and could be easily recovered and reused for six times without a considerable decrease in catalytic activity. Green reaction conditions, ease work-up, feasibility, cleaner reaction profile, simple purification, sustainable and stable recyclability of catalyst are some advantages of the present protocol.

Automated summary

A series of magnetic zinc ferrites modified SBA-15 supported ionic liquids have been synthesized and evaluated as effective catalysts for the one-pot multi-component reaction. The most active and suitable catalyst efficiently produced tetrahydrobenzo[b]pyrans in high to excellent yields at room temperature. The catalyst exhibited excellent stability and recyclability, making it a promising option for sustainable catalysis.