Hybrid magnetic materials (Fe3O4–κ-carrageenan) as catalysts for the Michael addition of aldehydes to nitroalkenes

Mak, Carmen A.; Ranjbar, Sara; Riente, Paola; Rodríguez‐Escrich, Carles; Pericàs, Miquel À.

doi:10.1016/j.tet.2014.06.063

Cited by 31 publications

(9 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, the volatiles were removed under a dynamic vacuum to yield a solid product. The resulting precursor was analyzed by ATR‐FTIR spectroscopy 55–57…”

Section: Methodsmentioning

confidence: 99%

Carrageenan–Silica Hybrid Nanoparticles Prepared by a Non‐Emulsion Method

2015

View full text Add to dashboard Cite

Spherical and monodispersed sub‐micrometer sized particles of organic–inorganic hybrids were prepared by means of a sol–gel non‐emulsion method using the biopolymer κ‐carrageenan and the alkoxysilane 3‐isocyanatopropyltriethoxysilane (ICPTES). The structural characterization of the carrageenan–silica hybrid particles was performed by using FTIR spectroscopy and solid‐state 29Si and 13C NMR spectroscopy and confirmed that κ‐carrageenan was covalently linked to the siliceous network via urethane bonds. Zeta‐potential measurements indicate the hybrids were functionalized on the surface with sulfonate groups from the polysaccharide. These hybrids display thermal sensitivity, which is of great relevance for biomedical applications such as drug encapsulation and thermally controlled drug‐delivery systems.

show abstract

“…Finally, the volatiles were removed under a dynamic vacuum to yield a solid product. The resulting precursor was analyzed by ATR‐FTIR spectroscopy 55–57…”

Section: Methodsmentioning

confidence: 99%

Carrageenan–Silica Hybrid Nanoparticles Prepared by a Non‐Emulsion Method

2015

View full text Add to dashboard Cite

show abstract

“…Nowadays magnetic materials have drawn extensive attention due to their potential applications in various fields such as catalysis 1 , optics 2 , separation 3 , enrichment 4 5 and magnetic properties 6 7 8 9 . Among them, BaFe 12 O 19 (BF) is an important magnet material because of its high Curie temperature, large saturation magnetization ( M s ), high magneto-crystalline anisotropy, good corrosion resistivity and excellent chemical stability 10 11 .…”

mentioning

confidence: 99%

BaFe12O19-chitosan Schiff-base Ag (I) complexes embedded in carbon nanotube networks for high-performance electromagnetic materials

Zhao

Xie

Guan

et al. 2015

Sci Rep

View full text Add to dashboard Cite

The multiwalled carbon nanotubes/BaFe12O19-chitosan (MCNTs/BF-CS) Schiff base Ag (I) complex composites were synthesized successfully by a chemical bonding method. The morphology and structures of the composites were characterized with electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction techniques. Their conductive properties were measured using a four-probe conductivity tester at room temperature, and their magnetic properties were tested by a vibrating sample magnetometer. The results show that the BF-CS Schiff base Ag (I) complexes are embedded into MCNT networks. When the mass ratio of MCNTs and BF-CS Schiff base is 0.95:1, the conductivity, Ms (saturation magnetization), Mr (residual magnetization), and Hc (coercivity) of the BF-CS Schiff base composites reach 1.908 S cm−1, 28.20 emu g−1, 16.66 emu g−1 and 3604.79 Oe, respectively. Finally, a possible magnetic mechanism of the composites has also been proposed.

show abstract

“…This proficiency is mainly due to an acid‐base interaction between the carboxylic acid functions of the biopolymer and the basic dye. We questioned whether such acid‐base interaction could be leveraged to link an amine organic catalyst to alginic acid gels, providing the first example of the utilization of alginates as support for chiral organic catalysts , . Even if the retaining of catalyst activity and selectivity in the gel structure was considered challenging, literature encouragement to our working plan was given by a few examples of non‐covalent immobilization of amine catalysts to acidic supports .…”

Section: Introductionmentioning

confidence: 99%

Adsorption of a Chiral Amine on Alginate Gel Beads and Evaluation of its Efficiency as Heterogeneous Enantioselective Catalyst

et al. 2019

View full text Add to dashboard Cite

A representative Lewis base organic catalyst (9‐amino‐9‐deoxy epi‐quinine, QNA) can be adsorbed in high yields onto acidic alginate gels (AGs) using a very simple and straightforward protocol. The resulting solvogel beads (QNA@AGs) are active as heterogeneous catalysts in the addition of aldehydes to nitroalkenes, affording the corresponding adducts in good yields and moderate to excellent diastereo‐ and enantio‐selectivities. In these reactions, the carboxylic functions of the biopolymer act as both acidic co‐catalyst and non‐covalent anchoring site for the tertiary amine catalyst (as observed by IR spectroscopy). Use of heterocationic gels, derived from alkaline earth metal gels by proton exchange, provided materials with better mechanical properties and higher porosities, ultimately resulting in higher catalytic activities. This work represents the first utilization of alginates, abundant and renewable biopolymers, as gel supports/media for asymmetric organocatalytic processes.

show abstract

Hybrid magnetic materials (Fe3O4–κ-carrageenan) as catalysts for the Michael addition of aldehydes to nitroalkenes

Cited by 31 publications

References 39 publications

Carrageenan–Silica Hybrid Nanoparticles Prepared by a Non‐Emulsion Method

Carrageenan–Silica Hybrid Nanoparticles Prepared by a Non‐Emulsion Method

BaFe12O19-chitosan Schiff-base Ag (I) complexes embedded in carbon nanotube networks for high-performance electromagnetic materials

Adsorption of a Chiral Amine on Alginate Gel Beads and Evaluation of its Efficiency as Heterogeneous Enantioselective Catalyst

Contact Info

Product

Resources

About