4151-97-7Relevant articles and documents
Cellulose sulfate: An efficient heterogeneous catalyst for the ring-opening of epoxides with alcohols and anilines
Chaudhary, Pooja,Deepa,Meena, Dhan Raj,Aalam, Mohd Jubair,Yadav, Geeta Devi,Singh, Surendra
supporting information, p. 1834 - 1846 (2021/05/10)
Cellulose sulfate was synthesized by esterification of α-cellulose with concentrated sulfuric acid at ?10°C in ethanol. Cellulose is mainly sulfated on 3-, 6- and 3, 6-positions of the cellulose. It acts as a heterogeneous catalyst for the ring-opening of epoxides with alcohols or anilines and the Friedel-Crafts reaction between N-benzylindole and crotonaldehyde at room temperature. Methanolysis of cyclic epoxides, styrene oxide, terminal aliphatic epoxides, and glycidyl ethers were carried out using the catalyst (0.4–6.8 mg/mmol of epoxide) and afforded the corresponding products in 53–97% isolated yields after 10 min–24 h. Cellulose sulfate was successfully recycled and reused up to 3 catalytic cycles for the ring-opening of styrene oxide with methanol.
MBA-cross-linked poly(N-vinyl-2-pyrrolidone)/ferric chloride macromolecular coordination complex as a novel and recyclable Lewis acid catalyst: Synthesis, characterization, and performance toward for regioselective ring-opening alcoholysis of epoxides
Rahmatpour, Ali,Zamani, Maryam
, (2021/09/30)
A novel macromolecular-metal coordination complex, MBA-cross-linked PNVP/FeCl3 material was fabricated by immobilization of water intolerant ferric chloride onto the porous cross-linked poly(N-vinyl-2-pyrrolidone) carrier beads as a macromolecular ligand or carrier which was prepared by suspension free-radical copolymerization of N-vinyl-2-pyrrolidone (NVP) and N,N′-methylene bis-acrylamide (MBA) as a crosslinking agent in water. The obtained PNVP/FeCl3 was characterized by UV/vis and FT-IR spectroscopies, TGA, FE-SEM, EDX, and ICP techniques. This heterogenized version of ferric chloride is a convenient and safe alternative to highly water intolerant ferric chloride. The catalytic performance of (PNVP/FeCl3) as an efficient and recyclable polymeric Lewis acid catalyst was appropriately probed in the regio-and stereoselective nucleophilic ring opening of various epoxides with various alcohols in excellent yields with TOF up to 182.48 h?1 without generating any waste. The activity data indicate that this heterogeneous catalyst is very active and could be easily recovered, and reused at least six times without appreciable loss of activity indicating its stability under experimental conditions.
Readily Scalable Methodology for the Synthesis of Nonsymmetric Glyceryl Diethers by a Tandem Acid-/Base-Catalyzed Process
Leal-Duaso, Alejandro,Gracia-Barberán, Sara,Mayoral, José A.,Garciá, José I.,Pires, Elisabet
, p. 154 - 162 (2020/02/04)
A useful optimized synthetic methodology has been designed for the synthesis of nonsymmetric glyceryl diethers from epichlorohydrin. A tandem process combining a cheap, heterogeneous, and fully recoverable acid catalyst and alkaline hydroxide is used for the synthesis of a variety of glycerol-derived ethers bearing different alkyl substituents in 1 and 3 positions. Different heterogeneous acid catalysts have been tested for the reaction of epichlorohydrin with several alcohols, the best results being obtained with readily available recoverable and inexpensive montmorillonite-K10 and Nafion NR50. For the second reaction step, potassium hydroxide is used. In all the cases, good yields of the desired glyceryl diethers are obtained in smooth reaction conditions, always with total conversion of epichlorohydrin and without the need of intermediate purification. Scale-up of the tandem process has been carried out with good results.
