scholarly journals Modified Cellulose with BINAP-Supported Rh as an Efficient Heterogeneous Catalyst for Asymmetric Hydrogenation

Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 83
Author(s):  
Cuiping Yu ◽  
Weilong Wu ◽  
Min Gao ◽  
Yu Liu
Keyword(s):  
Thermal Stability ◽  
Schiff Base ◽  
Asymmetric Catalysis ◽  
Supported Catalyst ◽  
Asymmetric Hydrogenation ◽  
Enantioselective Catalysis ◽  
Chiral Molecules ◽  
Modified Cellulose ◽  
Efficient Heterogeneous Catalyst

Asymmetric catalysis is the preferred method for the synthesis of pure chiral molecules in the fine chemical industry. Cellulose has long been sought as a support in enantioselective catalysis. Dialdehyde cellulose (DAC) is produced by the selective oxidation of cellulose and is used to bind 5,5′-diamino Binap by forming a Schiff base. Here, we report the synthesis of modified cellulose-supported Rh as a novel biomass-supported catalyst and the characterization of its morphology, composition, and thermal stability. DAC-BINAP-Rh was a very effective catalyst in the asymmetric hydrogenation of enamides and could be easily recycled. This work provides a novel supported catalyst that broadens the applications of cellulose in asymmetric catalysis.

Synthesis and Characterization of Some Functional Schiff Base Derivatives with Azobenzene Substituted Groups

2011 ◽  
Vol 197-198 ◽  
pp. 623-626 ◽  
Author(s):  
Ti Feng Jiao ◽  
Xu Hui Li ◽  
Jing Xin Zhou ◽  
Jing Ya Liang ◽  
Jing Ren
Keyword(s):  
Thermal Stability ◽  
Schiff Base ◽  
Aromatic Aldehydes ◽  
Molecular Structures ◽  
Aromatic Substituent ◽  
Schiff Base Derivatives ◽  
The Difference ◽  
Base Group ◽  
Thermal Stability Of

Some functional Schiff base derivatives with azobenzene substituted groups have been designed and synthesized from the reaction of aminoazobenzene with different aromatic aldehydes. It has been found that depending on the size of aromatic groups, the formed Schiff base derivatives showed different properties, indicating distinct regulation of molecular skeletons. UV and IR data confirmed commonly the formation of Schiff base as well as aromatic segment in molecular structures. Thermal analysis showed that the thermal stability of Schiff base molecules with naphthalene segment increased slightly in comparison with other derivatives. The difference of thermal stability is mainly attributed to the formation of Schiff base group and aromatic substituent groups in molecular structure. The present results have demonstrated that the special properties of Schiff base derivatives can be turned by modifying molecular structures of objective compounds with proper substituted groups, which show potential application in functional material field.

Asymmetric Catalysis, 154 [1]. New 1,1’-Binaphthyl Ligands for Enantioselective Catalysis

2003 ◽  
Vol 58 (9) ◽  
pp. 821-826 ◽  
Author(s):  
Henri Brunner ◽  
Matthias Weber ◽  
Manfred Zabel
Keyword(s):  
Asymmetric Catalysis ◽  
Catalytic Reactions ◽  
Enantioselective Catalysis ◽  
Synthesis And Characterization ◽  
Amino Groups ◽  
Binaphthyl Compounds

Chiral binaphthyl compounds, especially those with different substituents in 2- and 2’-position of the binaphthyl system, have gained interest as constituents of successful ligands in various catalytic reactions. Here, we present the synthesis and characterization of new binaphthyl ligands containing oxazoline, cyano and amide substituents in 2’-position in addition to methoxy, hydroxy or amino groups in 2-position. Starting from these compounds new ligands for enantioselective catalysis will be accessible.

scholarly journals Synthesis, Characterization of Cellulose Modified with 2-Mercaptobenzothiazole and Its Adsorption To Cu(II) Ion in Aqueous Solution

2015 ◽  
Vol 15 (2) ◽  
pp. 194-200 ◽  
Author(s):  
Ahmad Fatoni ◽  
Soerja Koesnarpadi ◽  
Nurlisa Hidayati
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Functional Group ◽  
Interaction Time ◽  
Ion Concentration ◽  
Adsorption Study ◽  
Initial Concentration ◽  
Influence Of Ph ◽  
Modified Cellulose

The modification of cellulose with 2-mercaptobenzhotiazole (MBT) through grafting and impregnating methods has been done. Modified cellulose used as adsorbent for Cu(II) ion in aqueous solution. The aims of research were modification cellulose with 3-chloropropyltrimethoxysilane and 2-mercaptobenzhotiazole (MBT), characterization of the modified cellulose with FTIR, SEM and XRD and adsorption study between cellulose-MBT adsorbent with Cu(II) ion in aqueous solution. The adsorbent of cellulose-MBT was synthesized by reflux process. Adsorption study between cellulose-MBT adsorbent with Cu(II) ion was investigated based on influence of pH solution, interaction time and initial concentration of Cu(II) ion. The result showed that activated cellulose can be modified with MBT to become cellulose-MBT adsorbent. The functional group of –C=N appeared at wavenumber 1658 cm-1 attributed to functional group of -C=N- is Schiff base of MBT. Presence functional group of S-H at cellulose-MBT adsorbent was not detected. The surface morphology of cellulose-MBT adsorbent after being interacted with Cu(II) ion was different before being interacted with Cu(II) ion. The diffractogram of cellulose-MBT adsorbent has similarity with cellulose-MBT adsorbent-Cu(II) ion. The optimum adsorption of Cu(II) ion was observed at pH 7.0 and 150 min of interaction time. Percentage of Cu(II) ion was absorbed by cellulose-MBT adsorbent tended to be constant after Cu(II) ion concentration 100 ppm.

Synthesis and Characterization of Some New Esters Containing Heterocyclic and Derived From Azo Dyes

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Zena G. Alrecabi ◽  
Zainab Amer ◽  
Naeemah Al-Lami
Keyword(s):  
Schiff Base ◽  
13C Nmr ◽  
Azo Dyes ◽  
Spectral Methods ◽  
Anthranilic Acid ◽  
Heterocyclic Compounds ◽  
Synthesis And Characterization ◽  
Cooh Group ◽  
Molecular Weights

This study including prepared new colored esters containing heterocyclic with high molecular weights. In the first part of work we synthesized azo dyes [1,2] from the reaction p-toluidine with β-naphthol and o-nitro phenol, thin we synthesized Schiff bases [3,4] by the reaction anthranilic acid with benzaldehyde and dimethyl benzaldehyde. The reaction azo dyes (contain OH group) with Schiff base (contain COOH group) these led to produce the new colored esters [A1-A4]. The second part of work was modification the (C=N-) group in esters to heterocyclic compounds by reacting with phenyl iso cyanide to produce new β-lactam [B1-B4] and with anthranilic acid to get new hydroquinazoline [C1-C4]. All these compounds were characterized by physical properties and spectral methods FTIR, 1H-NMR and 13C-NMR.

scholarly journals The Preparation and Characterization of Chitosan-Based Hydrogels Cross-Linked by Glyoxal

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2449
Author(s):  
Beata Kaczmarek-Szczepańska ◽  
Olha Mazur ◽  
Marta Michalska-Sionkowska ◽  
Krzysztof Łukowicz ◽  
Anna Maria Osyczka
Keyword(s):  
Thermal Stability ◽  
Tannic Acid ◽  
Dental Pulp ◽  
Blood Compatibility ◽  
Dental Pulp Cells ◽  
Preliminary Assessment ◽  
Human Dental Pulp Cells ◽  
Human Dental Pulp ◽  
Pulp Cells

In this study, hydrogels based on chitosan cross-linked by glyoxal have been investigated for potential medical applications. Hydrogels were loaded with tannic acid at different concentrations. The thermal stability and the polyphenol-releasing rate were determined. For a preliminary assessment of the clinical usefulness of the hydrogels, they were examined for blood compatibility and in the culture of human dental pulp cells (hDPC). The results showed that after immersion in a polyphenol solution, chitosan/glyoxal hydrogels remain nonhemolytic for erythrocytes, and we also did not observe the cytotoxic effect of hydrogels immersed in tannic acid (TA) solutions with different concentration. Tannic acid was successfully released from hydrogels, and its addition improved material thermal stability. Thus, the current findings open the possibility to consider such hydrogels in clinics.

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