scholarly journals Chiral Mesoporous Silica Materials: A Review on Synthetic Strategies and Applications

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3899 ◽  
Author(s):  
Mingshu Cui ◽  
Wei Zhang ◽  
Luyao Xie ◽  
Lu Chen ◽  
Lu Xu
Keyword(s):  
Mesoporous Silica ◽  
Asymmetric Catalysis ◽  
Textural Properties ◽  
Synthetic Methods ◽  
Synthesis Process ◽  
Chromatographic Separations ◽  
Chiral Compounds ◽  
Enantioselective Resolution ◽  
Enantiomer Excess ◽  
Effective Delivery

Because of its tunable textural properties and chirality feature, chiral mesoporous silica (CMS) gained significant consideration in many fields and has been developed rapidly in recent years. In this review, we provide an overview of synthesis strategies for fabricating CMS together with its main applications. The properties of CMS, including morphology and mesostructures and enantiomer excess (ee), can be altered according to the synthetic conditions during the synthesis process. Despite its primary stage, CMS has attracted extensive attention in many fields. In particular, CMS nanoparticles are widely used for enantioselective resolution and adsorption of chiral compounds with desirable separation capability. Also, CMS acts as a promising candidate for the effective delivery of chiral or achiral drugs to produce a chiral-responsive manner. Moreover, CMS also plays an important role in chromatographic separations and asymmetric catalysis. There has been an in-depth review of the synthetic methods and mechanisms of CMS. And this review aims to give a deep insight into the synthesis and application of CMS, especially in recent years, and highlights the significance that it may have in the future.

Recent Progress in Catalytic Enantioselective Desymmetrization of Prochiral Organosilanes for the Synthesis of Silicon-Stereogenic Compounds

Synlett ◽  
2017 ◽  
Vol 29 (04) ◽  
pp. 388-396 ◽  
Author(s):  
Ryo Shintani
Keyword(s):  
Asymmetric Catalysis ◽  
Recent Progress ◽  
Enantioselective Synthesis ◽  
Synthetic Methods ◽  
High Significance ◽  
Chiral Compounds ◽  
Silicon Carbon ◽  
Carbon Bonds

It is highly important to develop efficient synthetic methods for various enantioenriched chiral compounds due to their high significance in our life. In this regard, asymmetric catalysis is one of the most attractive ways of synthesizing such compounds from achiral precursors. Although various methods have been developed for the enantio­selective preparation of carbon-stereogenic compounds, the corresponding methods for silicon-stereogenic compounds are much less established. In particular, little progress has been made on catalytic enantioselective synthesis using prochiral organosilanes until recently. This account focuses on the recent progress in the catalytic enantio­selective preparation of silicon-stereogenic organosilanes through ­desymmetrization of prochiral organosilanes.1 Introduction2 Desymmetrization of Diorganodihydrosilanes3 Desymmetrization of Tetraorganosilanes3.1 Desymmetrization through Cleavage of Silicon–Carbon Bonds3.2 Desymmetrization without Cleavage of Silicon–Carbon Bonds4 Conclusion

scholarly journals Biogenic Synthesis of Silver Nanoparticles with Antimicrobial Properties

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Evangelia A Pavlatou
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Properties ◽  
Public Health Problem ◽  
Integrated Approach ◽  
Synthetic Methods ◽  
Synthesis Process ◽  
Major Public Health Problem ◽  
Biogenic Synthesis ◽  
Wide Range ◽  
Bacteria And Fungi

The transmission of a wide range of diseases, related to the infection by pathogenic microorganisms is a major public health problem that daily endangers the safety of human population. Silver has been thoroughly studied and used against bacteria due to its antimicrobial properties. Nanostructured silver gathers all the advantages of the silver itself, as well as the advanced performance of the nanomaterials. Thus, currently, silver nanoparticles constitute the most widely used kind of nanoparticles in biomedicine, due to their attractive antimicrobial properties. A variety of physical and chemical methods are employed for the AgNPs synthesis. However, many of them include the use of toxic reagents or require large amounts of energy, during the synthesis process. For this reason, many eco-friendly methods are proposed in order to synthesize AgNPs. Hence, biogenic synthesis of AgNPs, utilizing biological resources opens a novel route for the development of alternative production processes.These methods seem to have significant advantages, as the extracts contribute positively to the formation and enhancement of the antimicrobial activity of AgNPs, also acting as protective agents of the produced particles. In this review an integrated approach of AgNPs bio-synthetic methods using microorganisms, such as bacteria and fungi, plants and plant extracts, as well as several templates, like DNA and viruses is discussed, shedding light on the comparative advantages of them.

scholarly journals Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

2021 ◽  
Vol 17 ◽  
pp. 2729-2764
Author(s):  
Alemayehu Gashaw Woldegiorgis ◽  
Xufeng Lin
Keyword(s):  
Phosphoric Acid ◽  
Asymmetric Catalysis ◽  
Medicinal Chemistry ◽  
High Efficiency ◽  
Biologically Active ◽  
Chiral Compounds ◽  
Chiral Phosphoric Acid ◽  
Wide Range ◽  
Axially Chiral ◽  
Acid Catalyzed

In recent years, the synthesis of axially chiral compounds has received considerable attention due to their extensive application as biologically active compounds in medicinal chemistry and as chiral ligands in asymmetric catalysis. Chiral phosphoric acids are recognized as efficient organocatalysts for a variety of enantioselective transformations. In this review, we summarize the recent development of chiral phosphoric acid-catalyzed synthesis of a wide range of axially chiral biaryls, heterobiaryls, vinylarenes, N-arylamines, spiranes, and allenes with high efficiency and excellent stereoselectivity.

scholarly journals High Performance of Phenol Adsorption using Iron Based SBA-15 Synthesized by Loading-Microwave Method

2019 ◽  
Vol 35 (3) ◽  
pp. 1022-1028
Author(s):  
Yuvita Eka Pertiwi ◽  
Maria Ulfa
Keyword(s):  
Mesoporous Silica ◽  
Molecular Sieves ◽  
High Performance ◽  
Textural Properties ◽  
Hexagonal Structure ◽  
Kinetics Model ◽  
Element Analysis ◽  
Phenol Compounds ◽  
X Ray ◽  
Iron Based

The iron based mesoporous silica (Fe2O3/SBA-15) was studied for the first time for adsorption of phenol as a model adsorbate compound. The structural and textural properties of the synthesized samples were characterized by means of X-Ray Diffraction, Transmission Electron Microscopy, FTIR and element analysis techniques by Energy Dispersive X-Ray (EDX). The result of XRD analysis showed that mesoporous SBA-15 silica molecular sieves which modified with Fe2O3has a hexagonal structure with a pore size is 4.90 nm and iron contents (25.27%) were found on the surface of the Fe2O3/mesoporous silica SBA-15. While the FTIR analysis showed that Fe2O3/SBA-15 had functional group of assymetric Si-O-Si and Fe-O-Si which was found at 1085 cm-1 and 678 cm-1, respectively. Adsorption performance of Fe2O3/SBA-15 material investigated by phenol compounds as adsorbate model. The optimum contact time is 60 minutes and the Kinetics model of the mesoporous SBA-15 silica molecular sieves modified Fe2O3 can adsorb phenol compounds following the Kinetics Model Ho and McKay. The result optimum adsorption capacity occuring in the adsorption of phenol compounds by of the mesoporous SBA-15 silica molecular sieves modified Fe2O3 is 114.000 mg/g.

Well-ordered mesoporous silica and bioactive glasses: promise for improved hemostasis

2019 ◽  
Vol 7 (1) ◽  
pp. 31-50 ◽  
Author(s):  
Sara Pourshahrestani ◽  
Nahrizul Adib Kadri ◽  
Ehsan Zeimaran ◽  
Mark R. Towler
Keyword(s):  
Mesoporous Silica ◽  
Textural Properties ◽  
Ordered Mesoporous Silica ◽  
Bioactive Glasses ◽  
Ordered Mesoporous

Mesoporous silica and bioactive glasses with unique textural properties are new generations of inorganic hemostats with efficient hemostatic ability.

scholarly journals Dealing with Skin and Blood-Brain Barriers: The Unconventional Challenges of Mesoporous Silica Nanoparticles

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 250 ◽  
Author(s):  
Alessandra Nigro ◽  
Michele Pellegrino ◽  
Marianna Greco ◽  
Alessandra Comandè ◽  
Diego Sisci ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Biological Tissues ◽  
Drug Dosage ◽  
Synthesis Process ◽  
Extensive Literature ◽  
Innovative Strategies ◽  
Wide Range

Advances in nanotechnology for drug delivery are fostering significant progress in medicine and diagnostics. The multidisciplinary nature of the nanotechnology field encouraged the development of innovative strategies and materials to treat a wide range of diseases in a highly specific way, which allows reducing the drug dosage and, consequently, improving the patient’s compliance. Due to their good biocompatibility, easy synthesis, and high versatility, inorganic frameworks represent a valid tool to achieve this aim. In this context, Mesoporous Silica Nanoparticles (MSNs) are emerging in the biomedical field. For their ordered porosity and high functionalizable surface, achievable with an inexpensive synthesis process and being non-hazardous to biological tissues, MSNs offer ideal solutions to host, protect, and transport drugs to specific target sites. Extensive literature exists on the use of MSNs as targeted vehicles for systemic (chemo) therapy and for imaging/diagnostic purposes. However, the aim of this review is to give an overview of the last updates on the potential applications of the MSNs for Topical Drug Delivery (TDD) and as drug delivery systems into the brain, discussing their performances and advantages in dealing with these intriguing biological barriers.

Catalytic Asymmetric Synthesis of P-Stereogenic Phosphines: Beyond Precious Metals

Synlett ◽  
2020 ◽  
Author(s):  
David S. Glueck
Keyword(s):  
Asymmetric Synthesis ◽  
Asymmetric Catalysis ◽  
Palladium Catalysts ◽  
Precious Metals ◽  
Synthetic Methods ◽  
Secondary Phosphine ◽  
Phosphine Oxides ◽  
Chiral Epoxides ◽  
Earth Abundant ◽  
Limonene Oxide

AbstractMetal-catalyzed asymmetric synthesis of P-stereogenic phosphines is a potentially useful approach to a class of chiral ligands with valuable applications in asymmetric catalysis. We introduced this idea with chiral platinum and palladium catalysts, exploiting rapid pyramidal inversion in diastereomeric metal–phosphido complexes (ML*(PRR′)) to control phosphorus stereochemistry. This Account summarizes our attempts to develop related synthetic methods using earth-abundant metals, especially copper, in which weaker metal–ligand bonds and faster substitution processes were expected to result in more active catalysts. Indeed, precious metals were not required. Without any transition metals at all, we exploited related P-epimerization processes to prepare enantiomerically pure phosphiranes and secondary phosphine oxides (SPOs) from commercially available chiral epoxides.1 Introduction2 Copper-Catalyzed Phosphine Alkylation3 Copper-Catalyzed Tandem Phosphine Alkylation/Arylation4 Nickel-Catalyzed Phosphine Alkylation5 Proton-Mediated P-Epimerization in Synthesis of Chiral Phosphiranes6 Diastereoselective Synthesis of P-Stereogenic Secondary Phosphine Oxides (SPOs) from (+)-Limonene Oxide7 Conclusions

scholarly journals Modelling the release of biological molecules from ordered mesoporous silica

2014 ◽  
Vol 70 (a1) ◽  
pp. C1799-C1799
Author(s):  
Francisco Mariano-Neto ◽  
Cristiano Oliveira ◽  
Márcia Fantini ◽  
Leide Cavalcanti ◽  
Osvaldo Sant'Anna
Keyword(s):  
Theoretical Model ◽  
Mesoporous Silica ◽  
Least Squares Method ◽  
Biological Molecules ◽  
Synthesis Process ◽  
Ordered Mesoporous Silica ◽  
In Situ Studies ◽  
Ordered Mesoporous ◽  
In Situ Experiments

This work reports preliminary results of the application of a theoretical model [1] in the study of incorporation and release of biological molecules from the porous structure of the SBA-15 [2] ordered mesoporous silica. A theoretical model taking into account the shape and spatial coordination of the pores in the amorphous silica structure is fitted through a non-linear least-squares method and the behavior of the parameters obtained from curves acquired in-situ during incorporation and release experiments are interpreted in the context of different media. Preliminary studies included experiments regarding the coating of the SBA-15 silica with the Eudragit® polymer and the stability of SBA-15 in experimental media (water and PBS solution) and in simulated body fluids. Small angle X-ray scattering experiments were performed mainly with bovine serum albumin (BSA) and insulin, and showed the silica's capacity of sheltering those molecules inside its structure, as well as the influence of Eudragit® on their release dynamics. In-situ experiments made during the incorporation and release of insulin helped elucidate the dynamics of those phenomena, through the reinterpretation of the theoretical model, which was originally designed to study the synthesis process of SBA-15. In this model, fit parameters were monitored during the experiment and, from their behaviors, some conclusions are drawn, such as the delay in BSA release for the SBA-15 plus Eudragit® in gastric fluid. The in-situ studies of insulin loading showed that this molecule's uptake takes place in the course of a few minutes and that it remains inside the pores. Also the in-situ studies of insulin release showed that this molecule is protected inside the silica walls, and the use of Eudragit® is, in a way, optional.

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