FITC-Functionalized TiO2 Nanoparticles for Simultaneous Neuron Imaging and in Cell Photocatalysis

2014 ◽  
Vol 1694 ◽  
Author(s):  
Tina Zhang ◽  
Mary Ann Go ◽  
Christian Stricker ◽  
Vincent Daria ◽  
Antonio Tricoli
Keyword(s):  
Fluorescence Emission ◽  
Reaction Times ◽  
Fluorescein Isothiocyanate ◽  
Flame Spray ◽  
Reaction Conditions ◽  
Dye Loading ◽  
Lysine Concentration ◽  
Small Neuron ◽  
High Fluorescence ◽  
Neuron Imaging

ABSTRACTCrystalline TiO2 nanoparticles were produced by scalable flame spray pyrolysis of organometallic solutions. A protocol is presented for the optimized functionalization of these particles with fluorescein isothiocyanate (FITC), an important biomedical dye via a lysine linker. The pH, stoichiometry and time for lysine reaction were determined for highest dye loading and minimized degree of polylysine formation. Acidic reaction conditions, low lysine concentration and short reaction times were found to meet this aim. The resulting particles were used for imaging single neurons, showing high fluorescence emission and ability for the particles to diffuse into small neuron structures such as dendrites.

Synthesis of Phosphonates via Michaelis-Arbuzov Reaction

2017 ◽  
Vol 14 (6) ◽  
pp. 883-903 ◽  
Author(s):  
Boppudi Hari Babu ◽  
Gandavaram Syam Prasad ◽  
Chamarthi Naga Raju ◽  
Mandava Venkata Basaveswara Rao
Keyword(s):  
Reaction Times ◽  
Biologically Active ◽  
Fine Tuning ◽  
Arbuzov Reaction ◽  
Reaction Conditions ◽  
Solvent Type ◽  
Potential Applications ◽  
Synthetic Methodologies ◽  
Optimal Reaction ◽  
The Arbuzov Reaction

Background: Michaelis–Arbuzov reaction has played a key role for the synthesis of dialkyl or diaryl phosphonates by reacting various alkyl or aryl halides with trialkyl or triaryl phosphite. This reaction is very versatile in the formation of P-C bond from the reaction of aliphatic halides with phosphinites or phosphites to yield phosphonates, phosphinates, phosphine oxides. The Arbuzov reaction developed some methodologies, possible mechanistic pathways, selectivity, potential applications and biologically active various phosphonates. Objective: The synthesis of phosphonates via Michaelis–Arbuzov reaction with many new and fascinating methodologies were developed and disclosed in the literature, and these are explored in this review. Conclusion: This review has discussed past developments and vast potential applications of Arbuzov reaction in the synthesis of organophosphonates. As presented in this review, various synthetic methodologies were developed to prepare a large variety of phosphonates. Improvements in the reaction conditions of Lewis-acid mediated Arbuzov rearrangement as well as the development of MW-assisted Arbuzov rearrangement were discussed. Finally, to achieve high selectivities and yields, fine-tuning of reaction conditions including solvent type, temperature, and optimal reaction times to be considered.

scholarly journals Microwave-Assisted Asinger Synthesis of Thiazolines

2020 ◽  
Vol 3 (1) ◽  
pp. 27
Author(s):  
Raúl Eduardo Gordillo-Cruz ◽  
Liliana Gonzalez-Reyes ◽  
Milton Coporo-Reyes ◽  
Nieves Zavala-Segovia ◽  
Bernardo A. Frontana-Uribe ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Reaction Times ◽  
Reaction Conditions ◽  
Microwave Assisted

An array of 2,4-disubstituted thiazolines was obtained through Asinger reaction approach from the straightforward treatment of diverse aldehydes/ketones with 1-mercaptopropan-2-one, in the presence of NH3 assisted by microwave irradiation, displaying similar and sometimes higher yields, as well as shorter reaction times that traditional Asinger reaction conditions at room and lower temperatures.

scholarly journals The Eschenmoser coupling reaction under continuous-flow conditions

2011 ◽  
Vol 7 ◽  
pp. 1164-1172 ◽  
Author(s):  
Sukhdeep Singh ◽  
J Michael Köhler ◽  
Andreas Schober ◽  
G Alexander Groß
Keyword(s):  
Continuous Flow ◽  
Elevated Temperatures ◽  
Reaction Times ◽  
Coupling Reaction ◽  
Flow Chemistry ◽  
Flow Conditions ◽  
Reaction Conditions ◽  
Bond Forming ◽  
Carbon Carbon Bond ◽  
Reaction Proceeds

The Eschenmoser coupling is a useful carbon–carbon bond forming reaction which has been used in various different synthesis strategies. The reaction proceeds smoothly if S-alkylated ternary thioamides or thiolactames are used. In the case of S-alkylated secondary thioamides or thiolactames, the Eschenmoser coupling needs prolonged reaction times and elevated temperatures to deliver valuable yields. We have used a flow chemistry system to promote the Eschenmoser coupling under enhanced reaction conditions in order to convert the demanding precursors such as S-alkylated secondary thioamides and thiolactames in an efficient way. Under pressurized reaction conditions at about 220 °C, the desired Eschenmoser coupling products were obtained within 70 s residence time. The reaction kinetics was investigated and 15 examples of different building block combinations are given.

scholarly journals Hypochlorite-Activated Fluorescence Emission and Antibacterial Activities of Imidazole Derivatives for Biological Applications

2021 ◽  
Vol 9 ◽  
Author(s):  
Thanh Chung Pham ◽  
Van-Nghia Nguyen ◽  
Yeonghwan Choi ◽  
Dongwon Kim ◽  
Ok-Sang Jung ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Stokes Shift ◽  
Fluorescence Emission ◽  
Antibacterial Activities ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Fluorogenic Probe ◽  
High Fluorescence

The ability to detect hypochlorite (HOCl/ClO−) in vivo is of great importance to identify and visualize infection. Here, we report the use of imidazoline-2-thione (R1SR2) probes, which act to both sense ClO− and kill bacteria. The N2C=S moieties can recognize ClO− among various typical reactive oxygen species (ROS) and turn into imidazolium moieties (R1IR2) via desulfurization. This was observed through UV–vis absorption and fluorescence emission spectroscopy, with a high fluorescence emission quantum yield (ՓF = 43–99%) and large Stokes shift (∆v∼115 nm). Furthermore, the DIM probe, which was prepared by treating the DSM probe with ClO−, also displayed antibacterial efficacy toward not only Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) but also methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum ß-lactamase–producing Escherichia coli (ESBL-EC), that is, antibiotic-resistant bacteria. These results suggest that the DSM probe has great potential to carry out the dual roles of a fluorogenic probe and killer of bacteria.

Efficient synthesis of pyrido[2,3-d]pyrimidine-7-carboxylic acids catalyzed by a TiO2/SiO2 nanocomposite in aqueous media at room temperature

2018 ◽  
Vol 73 (9) ◽  
pp. 641-645 ◽  
Author(s):  
Sepehr Sadegh-Samiei ◽  
Shahrzad Abdolmohammadi
Keyword(s):  
Heterogeneous Catalyst ◽  
Carboxylic Acids ◽  
Room Temperature ◽  
Aqueous Media ◽  
Reaction Times ◽  
Molar Ratio ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Moderate Reaction ◽  
Recyclable Heterogeneous Catalyst

AbstractA novel and efficient synthesis of eight 5-aryl-1,3-dimethyl-2,4-dioxo-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids using a TiO2/SiO2 nanocomposite with a molar ratio of 1:1 as a recyclable heterogeneous catalyst is described. The desired products, five of which are new, are formed in short reaction times (2–3 h) with high to excellent yields (94%–98%) under very moderate reaction conditions (room temperature, aqueous media).

Deep eutectic solvent-catalyzed Meyer–Schuster rearrangement of propargylic alcohols under mild and bench reaction conditions

2020 ◽  
Vol 56 (96) ◽  
pp. 15165-15168
Author(s):  
Nicolás Ríos-Lombardía ◽  
Luciana Cicco ◽  
Kota Yamamoto ◽  
José A. Hernández-Fernández ◽  
Francisco Morís ◽  
...  
Keyword(s):  
Room Temperature ◽  
Deep Eutectic Solvent ◽  
Reaction Times ◽  
Reaction Conditions ◽  
Propargylic Alcohols ◽  
First Time

Faster, milder, greener…better! The Meyer–Schuster rearrangement is disclosed for the first time in a deep eutectic solvent, namely FeCl3·6H2O/glycerol (3 : 1), enabling the reaction at room temperature, under air and with short reaction times.

scholarly journals Ultrasound-promoted organocatalytic enamine–azide [3 + 2] cycloaddition reactions for the synthesis of ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones

2017 ◽  
Vol 13 ◽  
pp. 694-702 ◽  
Author(s):  
Gabriel P Costa ◽  
Natália Seus ◽  
Juliano A Roehrs ◽  
Raquel G Jacob ◽  
Ricardo F Schumacher ◽  
...  
Keyword(s):  
Reaction Times ◽  
Cycloaddition Reactions ◽  
Reaction Conditions ◽  
Keto Esters ◽  
Efficient Access ◽  
High Yields ◽  
Short Times

The use of sonochemistry is described in the organocatalytic enamine–azide [3 + 2] cycloaddition between 1,3-diketones and aryl azidophenyl selenides. These sonochemically promoted reactions were found to be amenable to a range of 1,3-diketones or aryl azidophenyl selenides, providing an efficient access to new ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones in good to excellent yields and short reaction times. In addition, this protocol was extended to β-keto esters, β-keto amides and α-cyano ketones. Selanyltriazoyl carboxylates, carboxamides and carbonitriles were synthesized in high yields at short times of reaction under very mild reaction conditions.

scholarly journals Photoluminescence in m-carborane–anthracene triads: a combined experimental and computational study

2018 ◽  
Vol 6 (42) ◽  
pp. 11336-11347 ◽  
Author(s):  
Mahdi Chaari ◽  
Zsolt Kelemen ◽  
José Giner Planas ◽  
Francesc Teixidor ◽  
Duane Choquesillo-Lazarte ◽  
...  
Keyword(s):  
Computational Study ◽  
Fluorescence Emission ◽  
Fluorescence Properties ◽  
Quantum Yields ◽  
Aggregate State ◽  
Fluorescence Quantum Yields ◽  
High Fluorescence

m-Carborane has demonstrated to be a perfect platform to boost the fluorescence properties of anthracene, giving rise to high fluorescence quantum yields in solution and also retaining fluorescence emission in the aggregate state.

scholarly journals The Role Ionic Liquid [BMIM][PF6] in One-Pot Synthesis of Tetrahydropyran Rings through Tandem Barbier–Prins Reaction

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2084
Author(s):  
Poliane K. Batista ◽  
João Marcos G. de O. Ferreira ◽  
Fabio P. L. Silva ◽  
Mario L. A. A Vasconcellos ◽  
Juliana A. Vale
Keyword(s):  
Ionic Liquid ◽  
Yield Loss ◽  
Allyl Bromide ◽  
Reaction Times ◽  
Prins Reaction ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Barbier Reaction ◽  
Significant Yield

Tetrahydropyran (THP) rings are common in several natural products, therefore, various strategies are being developed to synthesize these rings. The present work described the study of a one-pot synthesis of 2,4,6-trisubstituted tetrahydropyran compounds promoted by the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6] through a Barbier–Prins reaction between allyl bromide and aldehydes. The use of [BMIM][PF6] gave Prins products from several aldehydes in good yields and reaction times. We also found that the anion, PF6-, accelerates the Barbier reaction when used alone, and the excess SnBr2 from the reaction conditions of the Barbier reaction leads to the formation of the THP rings, thus acting as a catalyst for Prins cyclization. Additionally, we demonstrate that ionic liquid can be recovered and reused five times in the preparation of 4-bromo-tetrahydro-2,6-diphenyl-2H-pyran without significant yield loss.

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