Nanomagnetic NH2·MIL-101(Fe)/ED as a new highly efficient catalyst for the synthesis of thiopyran and oxospiro-indolinethiopyran derivatives

Abstract

ABSTRACT In this publication, we reported an efficient MOF-based catalytic system for the synthesis of thiopyran and oxospiro-indolinethiopyran derivatives. For the first time, magnetic NH2.MIL-101(Fe)/ED was synthesized through anchoring FeCl3 on CoFe2O4 magnetic nanoparticles surface and then 2-aminoterphthalic acid was used to form MOF structure. In the final step, metal centers were modified with ethylenediamine (ED). Different techniques such as Fourier transmission infrared spectroscopy, X-ray diffraction, Field emission scanning electron microscopy, Transmission electron microscopy, Brunauer–Emmett–Teller analysis, and Thermogravimetric analysis were used to characterize the catalyst structure. Also using X-ray crystallography, the structure of the final product was determined. Nanomagnetic NH2.MIL-101(Fe)/ED gave us a satisfactory answer, affording the corresponding products with high to excellent yields (up to 93% yield). It seems that among the other available procedures, this catalytic system provided higher final product yields which result from the superior activity of this synthesized catalyst. Highlights Designing an efficient basic metal-organic framework catalyst. Novel MOF-based catalytic system for scalable and high-yielding synthesis of thiopyran and oxospiro-indolinethiopyran derivatives. Easy access to important classes of building blocks. Simple work-up procedure, clean reaction profiles and excellent product yields.