Natural Acidic Ionic Liquid Immobilized on Magnetic Silica: Preparation and Catalytic Performance in Chemoselective Synthesis of Dicoumarols and Substituted Xanthene Derivatives

Abstract

A novel magnetically separable natural acidic ionic liquid immobilized on magnetic silica were fabricated by covalent bonding of thiamine (VB1) modified with (3‐glycidyloxypropyl)trimethoxysilane (GMSI) moiety on the silica modified Fe3O4. 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.

Phosphomolybdic acid immobilized chitosan/Fe3O4: an efficient catalyst for the N-alkylation of anilines

“…As a part of ongoing research into the efficient synthesis of heterocyclic compounds [32][33][34][35][36], in the present study, we describe a green and effective procedure for the Nalkylation of aromatic amines with alcohols using H At first, the reaction of aniline (1 mmol) and benzhydrol (1 mmol) in the presence of 0.05 g of the catalyst in various solvents at 60 o C was selected as a model reaction ( Table 1). The results indicated that, among all, C 2 H 5 OH/H 2 O (1:1) is the most effective solvent.…”

An Insight View on Synthetic Protocol, Mechanistic and Biological Aspects of Biscoumarin Derivatives

“…A novel, one‐pot and potent pathway to synthesize biscoumarins from aldehydes and 4HC via domino Knoevenagel–Michael reaction using tetramethylguanidium‐acetate [TMG][Ac] as an ionic liquid catalyst at room temperature has been presented by Zhu and colleagues ( Scheme : Method 6) . Azizi and co‐authors prepared a catalyst by natural acidic IL immobilized on magnetic silica (Fe 3 O 4 @SiO 2 @VB1‐Ni II ) and used this catalyst in protocol to form biscoumarin from 4HC and aldehyde in solvent free condition at 110 °C ( Scheme : Method 7) .…”

A rapid and quantitative synthesis of xanthene derivatives using sulfonated graphitic carbon nitride under ball‐milling

“…Xanthene and its derivatives are the most promising biologically active compounds with great pharmaceutical applicability [2][3][4][5][6]. Furthermore, these compounds have been utilized in local dyes [7], laser technologies [8,9], and photodynamic therapy [10]. Structures of some bioactive xanthenes (rhodamine, amsacrine, and RO67-4853) [11] are depicted in Figure 1.…”