Fe₃O₄ Nanoparticle-Supported Copper(I) Pybox Catalyst: Magnetically Recoverable Catalyst for Enantioselective Direct-Addition of Terminal Alkynes to Imines

Abstract

An Fe(3)O(4) nanoparticle-supported copper(I) pybox catalyst, which exhibits excellent reactivity and yields products with good enantioselectivity, was developed. As a proof of concept, six optically active propargyl amines were obtained in excellent yields. The catalyst can be magnetically removed and recycled easily six times without a decrease in activity or enantioselectivity.

Synthesis and Characterization of Fe3O4@SiO2 NPs as an Effective Catalyst for the Synthesis of Tetrahydrobenzo[a]xanthen-11-ones

“…6,7 Recently, functionalized magnetite nanoparticles were used as efficient catalytic systems in many chemical transformations including synthesis of α-amino nitriles, 8 1,1-diacetates from aldehydes, 9 diazepine derivatives, 10 indazolo[2,1-b]phthalazine-triones and pyrazolo [1,2-b]phthalazine-diones, 11 3,4-dihydropyrimidin-2(1H)-ones, 12 2-amino-4H-chromen-4-yl phosphonates, 13 1,4-dihydropyridines 14 and pyrrole synthesis. 15 In addition, a series of organic reactions such as Knoevenagel condensation/Michael addition, 16 Suzuki/Heck cross-coupling, 17 asymmetric aldol reaction, 18 Suzuki coupling, 19 asymmetric hydrogenation of aromatic ketones, 20 acetalization reaction, 21 Ritter reaction, 22 23 Henry reaction, 24 enantioselective directaddition of terminal alkynes to imines 25 have been done using functionalized nanostructures.…”

Biguanide-Functionalized Fe3O4/SiO2Magnetic Nanoparticles: An Efficient Heterogeneous Organosuperbase Catalyst for Various Organic Transformations in Aqueous Media

“…This modification was performed according to the known reaction sequence. 15 , which are due to the COO-Fe bond and confirm the complexation between the carboxylate moiety of citrate groups and iron ions on the magnetite nanoparticles surface. 13 In the case of Fe 3 O 4 /SiO 2 nanoparticles (curve b), the sharp band at 1090 cm -1 is corresponding to Si-O-Si anti-symmetric stretching vibration, being indicative of the existence of a SiO 2 layer around the Fe 3 O 4 nanoparticles.…”

“…First, chloropropyl-modified silica-coated magnetic nanoparticles were prepared following the modified procedure of Zeng et al 15 After 1 mL (5 mmol) of CPTS was dissolved in 100 mL of dried toluene, this mixture was added to 1 g of Fe 3 O 4 /SiO 2 and the solution was stirred for 18 h at 60 °C. The chloropropyl-functionalized solid (Fe 3 O 4 / SiO 2 -Cl) was washed with toluene, separated by a magnet, and dried in vacuum.…”

Fe3O4@SiO2-NH2 Nanocomposite as a Robust and Effective Catalyst for the One-pot Synthesis of Polysubstituted Dihydropyridines

“…29 In continuation of the progress of the synthetic approach to the synthesis of heterocyclic compounds using reusable nanocatalysts and multi-component reactions, [30][31][32][33][34] herein we report a simple, efficient, mild and practical method for the synthesis of polysubstituted dihydropyridines via a four-component coupling reaction in the presence of Fe 3 O 4 @SiO 2 -NH 2 nanocomposite as a green and environmentally benign nanocatalyst in ethanol as solvent at room temperature (Scheme 1).…”