Green Preparation of Carbon Dots from Lycium Ruthenicum for Anti-counterfeiting

2021 ◽  
Author(s):  
Ting Guo ◽  
Xinyi Jiang ◽  
Xiaolin Hu ◽  
Xinyu Sun ◽  
Liangzhe Chen ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Uv Light ◽  
High Yield ◽  
Surface Functional Groups ◽  
Reaction Conditions ◽  
Complex Processes ◽  
Ink Jet ◽  
Lycium Ruthenicum ◽  
Alternative Material ◽  
One Step

Carbon dots (CDs) with excellent fluorescent performance are a potential material to restrain fakes, but the complex processes, high cost, and toxicity impede their application. Here, Lycium ruthenicum is employed as the carbon source, and eco-friendly CDs are obtained via a one-step hydrothermal method. The reaction conditions such as dosage, temperature, and time are optimized to achieve high yield, and the morphology, surface functional groups, and optical properties are characterized by scientific instruments. The results show that the spherical CDs with a diameter of 1.83 ± 0.30 nm have excellent solubility and a strong absorption peak at 285 nm. Subsequently, CDs were made into fluorescent inks; an ink-jet printer and a fountain pen are selected to examine the anti-counterfeit effect. Notably, the encrypted patterns can be hidden and perceived easily under natural light and UV light. Hence, these prepared CDs are expected to be an alternative material to be applied in the security field.

Fast one-step synthesis of N-doped carbon dots by pyrolyzing ethanolamine

2014 ◽  
Vol 2 (36) ◽  
pp. 7477-7481 ◽  
Author(s):  
Xinwei Dong ◽  
Yanjie Su ◽  
Huijuan Geng ◽  
Zhongli Li ◽  
Chao Yang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Dots ◽  
High Yield ◽  
One Step ◽  
Doped Carbon Dots

N-doped CDs can be obtained directly with high yield by pyrolyzing ethanolamine in air within just 7 minutes with the assistance of hydrogen peroxide.

scholarly journals Phosgene-free synthesis of 1,3-diphenylurea via catalyzed reductive carbonylation of nitrobenzene

2012 ◽  
Vol 84 (3) ◽  
pp. 473-484 ◽  
Author(s):  
Andrea Vavasori ◽  
Lucio Ronchin
Keyword(s):  
Phenyl Isocyanate ◽  
High Yield ◽  
Diphosphine Ligands ◽  
Alternative Route ◽  
Reaction Conditions ◽  
Bite Angle ◽  
Reductive Carbonylation ◽  
One Step ◽  
Optimum Reaction ◽  
Synthetic Intermediate

1,3-Diphenylurea (DPU) has been proposed as a synthetic intermediate for phosgene-free synthesis of methyl N-phenylcarbamate and phenyl isocyanate, which are easily obtained from the urea by reaction with methanol. Such an alternative route to synthesis of carbamates and isocyanates necessitates an improved phosgene-free synthesis of the corresponding urea. In this work, it is reported that Pd(II)-diphosphine catalyzed reductive carbonylation of nitrobenzene in acetic acid (AcOH)-methanol proceeds in high yield and selectivity as a one-step synthesis of DPU. We have found that the catalytic activity and selectivity of this process depends on solvent composition and on the bite angle of the diphosphine ligands. Under optimum reaction conditions, yields in excess of 90 molar % and near-quantitative selectivity can be achieved.

scholarly journals Engineering Mitochondriotropic Carbon Dots for Targeting Cancer Cells

2021 ◽  
Vol 14 (9) ◽  
pp. 932
Author(s):  
Archontia Kaminari ◽  
Eleni Nikoli ◽  
Alexandros Athanasopoulos ◽  
Elias Sakellis ◽  
Zili Sideratou ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Alkyl Chain ◽  
Visible Spectrum ◽  
Enhanced Fluorescence ◽  
Reaction Conditions ◽  
Low Concentrations ◽  
One Step ◽  
The One ◽  
Chain Lengths

Aiming to understand and enhance the capacity of carbon dots (CDs) to transport through cell membranes and target subcellular organelles—in particular, mitochondria—a series of nitrogen-doped CDs were prepared by the one-step microwave-assisted pyrolysis of citric acid and ethylenediamine. Following optimization of the reaction conditions for maximum fluorescence, functionalization at various degrees with alkylated triphenylphosphonium functional groups of two different alkyl chain lengths afforded a series of functionalized CDs that exhibited either lysosome or mitochondria subcellular localization. Further functionalization with rhodamine B enabled enhanced fluorescence imaging capabilities in the visible spectrum and allowed the use of low quantities of CDs in relevant experiments. It was thus possible, by the appropriate selection of the alkyl chain length and degree of functionalization, to attain successful mitochondrial targeting, while preserving non-toxicity and biocompatibility. In vitro cell experiments performed on normal as well as cancer cell lines proved their non-cytotoxic character and imaging potential, even at very low concentrations, by fluorescence microscopy. Precise targeting of mitochondria is feasible with carefully designed CDs that, furthermore, are specifically internalized in cells and cell mitochondria of high transmembrane potential and thus exhibit selective uptake in malignant cells compared to normal cells.

One-Step Synthesis of Water-Soluble Fluorescent Carbon Dots

2015 ◽  
Vol 815 ◽  
pp. 434-439
Author(s):  
Fan Li ◽  
Chang Jun Liu ◽  
Jian Yang ◽  
Feng Tian ◽  
Rui Xin Li ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Heating Temperature ◽  
Nitrogen Atmosphere ◽  
Water Soluble ◽  
Ammonium Citrate ◽  
High Yield ◽  
Transmission Electron ◽  
Relative Quantum ◽  
One Step ◽  
Fluorescent Carbon Dots

Water-soluble carbon dots (CDs) with high yield were synthesized by a facile, one-step incomplete pyrolytic route under nitrogen atmosphere or air using ammonium citrate as carbon source. Photoluminescence (PL) spectrum, Fourier transform infrared (FTIR) absorption and high-resolution transmission electron microscopy (HRTEM) were used to determine the characteristics of the CDs. Though CDs could be prepared from 150 oC to 400 oC, the highest yield of CDs (17.5%) was achieved at the heating temperature of 150 oC in air, so did the relative quantum yield. The as-prepared CDs showed excellent biocompatibility and had been tentatively used in cell imaging.

Direct Cyclization of Alkenyl Thioester via Transition Metal‐hydrogen Atom Transfer/radical‐polar Crossover Mechanism

2019 ◽  
Author(s):  
Shiori Date ◽  
Kensei Hamasaki ◽  
Karen Sunagawa ◽  
Hiroki Koyama ◽  
Chikayoshi Sebe ◽  
...  
Keyword(s):  
Natural Products ◽  
Hydrogen Atom ◽  
Transition Metal ◽  
Hydrogen Atom Transfer ◽  
Synthetic Method ◽  
Atom Transfer ◽  
Reaction Conditions ◽  
Hydride Hydrogen ◽  
Sulfur Heterocycles ◽  
One Step

<div>We report here a catalytic, Markovnikov selective, and scalable synthetic method for the synthesis of saturated sulfur heterocycles, which are found in the structures of pharmaceuticals and natural products, in one step from an alkenyl thioester. Unlike a potentially labile alkenyl thiol, an alkenyl thioester is stable and easy to prepare. The powerful Co catalysis via a cobalt hydride hydrogen atom transfer and radical-polar crossover mechanism enabled simultaneous cyclization and deprotection. The substrate scope was expanded by the extensive optimization of the reaction conditions and tuning of the thioester unit.</div>

Gold Catalyzed Hydroamination of Propargylic Alcohols: Controlling Divergent Reaction Pathways to Access 1,3-Aminoalcohols, 3-Hydroxyketones or 3-Aminoketones

2018 ◽  
Author(s):  
Victor Laserna ◽  
Tom Sheppard
Keyword(s):  
Gold Catalysis ◽  
Reaction Pathways ◽  
High Yield ◽  
Reaction Conditions ◽  
Propargylic Alcohols ◽  
Catalytic Quantity ◽  
Selective Formation ◽  
General Method

A versatile approach to the valorization of propargylic alcohols is reported, enabling controlled access to three different products from the same starting materials. Firstly, a general method for the hydroamination of propargylic alcohols with anilines is described using gold catalysis to give 3-hydroxy imines with complete regioselectivity. These 3-hydroxyimines can be reduced to give 1,3-aminoalcohols with high syn seletivity. Alternatively, by using a catalytic quantity of aniline, 3-hydroxyketones can be obtained in high yield directly from propargylic alcohols. Further manipulation of the reaction conditions enables the selective formation of 3-aminoketones via a rearrangement/hydroamination pathway.<br>

A Simple Synthesis of the Anticancer Drug Altretamine

2020 ◽  
Vol 17 (8) ◽  
pp. 628-630
Author(s):  
Vu Binh Duong ◽  
Pham Van Hien ◽  
Tran Thai Ngoc ◽  
Phan Dinh Chau ◽  
Tran Khac Vu
Keyword(s):  
Aqueous Solution ◽  
Anticancer Drug ◽  
Potassium Hydroxide ◽  
Large Scale ◽  
Synthesis Method ◽  
Practical Method ◽  
Cyanuric Chloride ◽  
Simple Synthesis ◽  
High Yield ◽  
One Step

A simple and practical method for the synthesis on a large scale of altretamine (1), a wellknown antitumor drug, has been successfully developed. The synthesis method involves the conversion of cyanuric chloride (2) into altretamine (1) by dimethylamination of 2 with an aqueous solution of 40% dimethylamine and potassium hydroxide in 1, -dioxan 4in one step to give altretamine (1) in high yield.

Addition of Tetrachloromethane to 1,5-Hexadiene

1992 ◽  
Vol 57 (2) ◽  
pp. 393-396 ◽  
Author(s):  
Martin Kotora ◽  
Milan Hájek
Keyword(s):  
Palladium Catalyst ◽  
Adduct Formation ◽  
High Yield ◽  
Reaction Conditions ◽  
Dibenzoyl Peroxide

The 2 : 1 adduct as the final product of the addition of tetrachloromethane to 1,5-hexadiene catalyzed by copper(I)-butylamine complex was obtained in high yield (96%) under mild reaction conditions. Predominant 1 : 1 adduct formation was observed in the presence of a palladium catalyst or dibenzoyl peroxide initiator.

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