Catalytic Role of Metal Nanoparticles in Selectivity Control over Photodehydrogenative Coupling of Primary Amines to Imines and Secondary Amines

ACS Catalysis ◽  
2021 ◽  
pp. 6656-6661
Author(s):  
Jin Yu ◽  
Qi Liu ◽  
Wei Qiao ◽  
Dongdong Lv ◽  
Yaru Li ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Secondary Amines ◽  
Primary Amines ◽  
Catalytic Role ◽  
Selectivity Control

scholarly journals Hydrothermal Water Enabling One-Pot Transformation of Amines to Alcohols

2021 ◽  
Author(s):  
Lanxin Wu ◽  
Jiong Cheng ◽  
Xiaoguang Wang ◽  
Yang Yang
Keyword(s):  
Glutamic Acid ◽  
Nucleophilic Attack ◽  
Primary Amines ◽  
Primary Alcohols ◽  
Subsequent Reduction ◽  
One Pot ◽  
Selective Transformation ◽  
Catalytic Role ◽  
Hydrothermal Water

While the amination of primary alcohols to amines is quite normal, the reverse reaction, deamination of amines to alcohols is rare. Recent advances achieve the transformation by catalytic multistep processes. We report a one-pot method that enables water nucleophilic attack of amines through the unique catalytic role of hydrothermal water. By achieving dehydrogenation of amines or building targeting group, we fulfilled amines transformation by subsequent reduction or direct deamination, which could further link to the utilization of naturally abundant glutamic acid. The method avoids oxidants, catalysts or multistep, thus achieves simple, green and selective transformation of primary amines.

scholarly journals Hydrothermal Water Enabling One-Pot Transformation of Amines to Alcohols

2021 ◽  
Author(s):  
Lanxin Wu ◽  
Jiong Cheng ◽  
Xiaoguang Wang ◽  
Yang Yang
Keyword(s):  
Glutamic Acid ◽  
Nucleophilic Attack ◽  
Primary Amines ◽  
Primary Alcohols ◽  
Subsequent Reduction ◽  
One Pot ◽  
Selective Transformation ◽  
Catalytic Role ◽  
Hydrothermal Water

While the amination of primary alcohols to amines is quite normal, the reverse reaction, deamination of amines to alcohols is rare. Recent advances achieve the transformation by catalytic multistep processes. We report a one-pot method that enables water nucleophilic attack of amines through the unique catalytic role of hydrothermal water. By achieving dehydrogenation of amines or building targeting group, we fulfilled amines transformation by subsequent reduction or direct deamination, which could further link to the utilization of naturally abundant glutamic acid. The method avoids oxidants, catalysts or multistep, thus achieves simple, green and selective transformation of primary amines.

Acceptorless amine dehydrogenation and transamination using Pd-doped layered double hydroxides

2018 ◽  
Author(s):  
Diana Ainembabazi ◽  
Nan An ◽  
Jinesh Manayil ◽  
Kare Wilson ◽  
Adam Lee ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Oxidation States ◽  
Secondary Amines ◽  
Primary Amines ◽  
Acid Dissolution ◽  
Oxidative Amination ◽  
Strong Function ◽  
Excellent Activity ◽  
High Yields ◽  
Double Hydroxides

<div> <p>The synthesis, characterization, and activity of Pd-doped layered double hydroxides (Pd-LDHs) for for acceptorless amine dehydrogenation is reported. These multifunctional catalysts comprise Brønsted basic and Lewis acidic surface sites that stabilize Pd species in 0, 2+, and 4+ oxidation states. Pd speciation and corresponding cataytic performance is a strong function of metal loading. Excellent activity is observed for the oxidative transamination of primary amines and acceptorless dehydrogenation of secondary amines to secondary imines using a low Pd loading (0.5 mol%), without the need for oxidants. N-heterocycles, such as indoline, 1,2,3,4-tetrahydroquinoline, and piperidine, are dehydrogenated to the corresponding aromatics with high yields. The relative yields of secondary imines are proportional to the calculated free energy of reaction, while yields for oxidative amination correlate with the electrophilicity of primary imine intermediates. Reversible amine dehydrogenation and imine hydrogenation determine the relative imine:amine selectivity. Poisoning tests evidence that Pd-LDHs operate heterogeneously, with negligible metal leaching; catalysts can be regenerated by acid dissolution and re-precipitation.</p> </div> <br>

scholarly journals Toward a Better Understanding of Metal Nanoparticles, a Novel Strategy from Eucalyptus Plants

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 929
Author(s):  
Hanadi Sawalha ◽  
Rambod Abiri ◽  
Ruzana Sanusi ◽  
Noor Azmi Shaharuddin ◽  
Aida Atiqah Mohd Noor ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Woody Plants ◽  
Woody Species ◽  
Forest Products ◽  
Ideal Candidate ◽  
Promising Tool ◽  
Novel Strategy ◽  
The Ideal

Nanotechnology is a promising tool that has opened the doors of improvement to the quality of human’s lives through its potential in numerous technological aspects. Green chemistry of nanoscale materials (1–100 nm) is as an effective and sustainable strategy to manufacture homogeneous nanoparticles (NPs) with unique properties, thus making the synthesis of green NPs, especially metal nanoparticles (MNPs), the scientist’s core theme. Researchers have tested different organisms to manufacture MNPs and the results of experiments confirmed that plants tend to be the ideal candidate amongst all entities and are suitable to synthesize a wide variety of MNPs. Natural and cultivated Eucalyptus forests are among woody plants used for landscape beautification and as forest products. The present review has been written to reflect the efficacious role of Eucalyptus in the synthesis of MNPs. To better understand this, the route of extracting MNPs from plants, in general, and Eucalyptus, in particular, are discussed. Furthermore, the crucial factors influencing the process of MNP synthesis from Eucalyptus as well as their characterization and recent applications are highlighted. Information gathered in this review is useful to build a basis for new prospective research ideas on how to exploit this woody species in the production of MNPs. Nevertheless, there is a necessity to feed the scientific field with further investigations on wider applications of Eucalyptus-derived MNPs.

scholarly journals Flammable gases produced by TiO2 nanoparticles under magnetic stirring in water

Friction ◽  
2021 ◽  
Author(s):  
Pengcheng Li ◽  
Chongyang Tang ◽  
Xiangheng Xiao ◽  
Yanmin Jia ◽  
Wanping Chen
Keyword(s):  
Tio2 Nanoparticles ◽  
Quartz Glass ◽  
Dye Degradation ◽  
Mechanical Energy ◽  
Chemical Energy ◽  
Magnetic Stirring ◽  
Catalytic Role ◽  
Nanostructured Semiconductors

AbstractThe friction between nanomaterials and Teflon magnetic stirring rods has recently drawn much attention for its role in dye degradation by magnetic stirring in dark. Presently the friction between TiO2 nanoparticles and magnetic stirring rods in water has been deliberately enhanced and explored. As much as 1.00 g TiO2 nanoparticles were dispersed in 50 mL water in 100 mL quartz glass reactor, which got gas-closed with about 50 mL air and a Teflon magnetic stirring rod in it. The suspension in the reactor was magnetically stirred in dark. Flammable gases of 22.00 ppm CO, 2.45 ppm CH4, and 0.75 ppm H2 were surprisingly observed after 50 h of magnetic stirring. For reference, only 1.78 ppm CO, 2.17 ppm CH4, and 0.33 ppm H2 were obtained after the same time of magnetic stirring without TiO2 nanoparticles. Four magnetic stirring rods were simultaneously employed to further enhance the stirring, and as much as 30.04 ppm CO, 2.61 ppm CH4, and 8.98 ppm H2 were produced after 50 h of magnetic stirring. A mechanism for the catalytic role of TiO2 nanoparticles in producing the flammable gases is established, in which mechanical energy is absorbed through friction by TiO2 nanoparticles and converted into chemical energy for the reduction of CO2 and H2O. This finding clearly demonstrates a great potential for nanostructured semiconductors to utilize mechanical energy through friction for the production of flammable gases.

scholarly journals Catalytic role of histidine 147 in Escherichia coli thymidylate synthase

1989 ◽  
Vol 264 (32) ◽  
pp. 19132-19137
Author(s):  
I K Dev ◽  
B B Yates ◽  
J Atashi ◽  
W S Dallas
Keyword(s):  
Escherichia Coli ◽  
Thymidylate Synthase ◽  
Catalytic Role
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