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Natural Acidic Ionic Liquid Immobilized on Magnetic Silica: Preparation and Catalytic Performance in Chemoselective Synthesis of Dicoumarols and Substituted Xanthene Derivatives
Author(s) -
Azizi Najmedin,
Abbasi Faezeh,
AbdoliSenejani Masumeh
Publication year - 2018
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201800138
Subject(s) - ionic liquid , thermogravimetric analysis , xanthene , catalysis , moiety , knoevenagel condensation , chemistry , cascade reaction , organic chemistry , materials science , chemical engineering , engineering
A novel magnetically separable natural acidic ionic liquid immobilized on magnetic silica were fabricated by covalent bonding of thiamine (VB 1 ) modified with (3‐glycidyloxypropyl)trimethoxysilane (GMSI) moiety on the silica modified Fe 3 O 4 . The catalytic properties have been evaluated in one‐pot multi‐component synthesis of biscoumarins and substituted xanthene derivatives through the Domino Knoevenagel‐Michael reaction of a wide range of substrates under solvent free conditions. A variety of readily accessible aldehydes with different substituted functional groups have been converted to biscoumarins with good to excellent isolated yields and short reaction times. The novel nanocatalyst was characterized by infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), scanning electron microscopy (SEM/EDS) and thermogravimetric (TG) analysis. The catalyst was reused up to five consecutive cycles with high activity and selectivity and separated easily from the reaction mixture by an external magnetic field.