Bispentiptycenyl-N-Heterocyclic Carbene (NHC) Gold Complexes: Highly Active Catalysts for the Room Temperature Hydration of Alkynes

2018 ◽  
Vol 360 (18) ◽  
pp. 3572-3578 ◽  
Author(s):  
Maximillian Heidrich ◽  
Marvin Bergmann ◽  
Dorian Müller-Borges ◽  
Herbert Plenio
Keyword(s):  
Room Temperature ◽  
Gold Complexes ◽  
Highly Active

scholarly journals H/D Exchange Under Mild Conditions in Arenes and Unactivated Alkanes with C6D6 and D2O Using Rigid, Electron-rich Iridium PCP Pincer Complexes

2020 ◽  
Author(s):  
Joel D. Smith ◽  
George Durrant ◽  
Daniel Ess ◽  
Warren Piers
Keyword(s):  
Hydrogen Isotope ◽  
Isotope Exchange ◽  
Room Temperature ◽  
Pincer Complexes ◽  
Synthesis And Characterization ◽  
Hydrogen Isotope Exchange ◽  
Mild Conditions ◽  
Highly Active ◽  
Pcp Pincer

<div>The synthesis and characterization of an iridium polyhydride complex (Ir-H4)</div><div>supported by an electron-rich PCP framework is described. This complex readily loses molecular</div><div>hydrogen allowing for rapid room temperature hydrogen isotope exchange (HIE) at the hydridic</div><div>positions and the α-C-H site of the ligand with deuterated solvents such as benzene-d6, toluene-d8</div><div>and THF-d8. The removal of 1-2 equivalents of molecular H2 forms unsaturated iridium carbene</div><div>trihydride (Ir-H3) or monohydride (Ir-H) compounds that are able to create further unsaturation</div><div>by reversibly transferring a hydride to the ligand carbene carbon. These species are highly active</div><div>hydrogen isotope exchange (HIE) catalysts using C6D6 or D2O as deuterium sources for the</div><div>deuteration of a variety of substrates. By modifying conditions to influence the Ir-Hn speciation,</div><div>deuteration levels can range from near exhaustive to selective only for sterically accessible sites.</div><div>Preparative level deuterations of select substrates were performed allowing for procurement of</div><div>>95% deuterated compounds in excellent isolated yields; the catalyst can be regenerated by</div><div>treatment of residues with H2 and is still active for further reactions.</div>

scholarly journals Dinuclear thiazolylidene copper complex as highly active catalyst for azid–alkyne cycloadditions

2016 ◽  
Vol 12 ◽  
pp. 1566-1572 ◽  
Author(s):  
Anne L Schöffler ◽  
Ata Makarem ◽  
Frank Rominger ◽  
Bernd F Straub
Keyword(s):  
Acetic Acid ◽  
Organic Solvents ◽  
Copper Complex ◽  
Room Temperature ◽  
Active Catalyst ◽  
Catalyst Design ◽  
Ancillary Ligand ◽  
Click Reactions ◽  
Highly Active ◽  
Cost Efficient

A dinuclear N-heterocyclic carbene (NHC) copper complex efficiently catalyzes azide–alkyne cycloaddition (CuAAC) “click” reactions. The ancillary ligand comprises two 4,5-dimethyl-1,3-thiazol-2-ylidene units and an ethylene linker. The three-step preparation of the complex from commercially available starting compounds is more straightforward and cost-efficient than that of the previously described 1,2,4-triazol-5-ylidene derivatives. Kinetic experiments revealed its high catalytic CuAAC activity in organic solvents at room temperature. The activity increases upon addition of acetic acid, particularly for more acidic alkyne substrates. The modular catalyst design renders possible the exchange of N-heterocyclic carbene, linker, sacrificial ligand, and counter ion.

Fabrication of Pd/CeO2 nanocubes as highly efficient catalysts for degradation of formaldehyde at room temperature

2021 ◽  
Author(s):  
Yafeng Chen ◽  
Guimin Jiang ◽  
Xiangzhi Cui ◽  
Zuotai Zhang ◽  
Xinmei Hou
Keyword(s):  
Room Temperature ◽  
Complete Decomposition ◽  
Highly Efficient ◽  
Highly Active ◽  
Surface Active

The highly active Pd/CeO2 nanocube interface guarantees a high percentage of metallic Pd and the surface active O species is responsible for the complete decomposition of formaldehyde.

Acrasin, the Chemotactic Agent in Cellular Slime Moulds

1956 ◽  
Vol 33 (4) ◽  
pp. 645-657
Author(s):  
B. M. SHAFFER
Keyword(s):  
Room Temperature ◽  
Dialysis Membrane ◽  
Relay System ◽  
Highly Active ◽  
Slime Moulds ◽  
Cellular Slime ◽  
Set Up ◽  
Cellular Slime Moulds ◽  
Extracellular Slime ◽  
Do So

1. A study has been made of acrasin, the agent inducing chemotaxis in the amoebae of cellular slime moulds. 2. A method has been developed for subjecting sensitive amoebae to a fluctuating gradient set up by an artificial source that can be renewed at intervals of as little as a few seconds with fresh test solution. 3. Amoebae orient to a gradient maintained with the cell-free liquid freshly obtained from the immediate surroundings of a natural source. 4. Acrasin solution as secreted loses its activity very rapidly at room temperature. 5. A highly active stable solid is obtained by drying methanolic culture extracts; it resists boiling and exposure to acids and alkalis. Its solubility decreases rapidly in passing up the alcohol series. 6. The original instability has been shown to be due to the presence of another extracellular slime-mould product, possibly an enzyme; it, unlike acrasin, cannot pass rapidly across a dialysis membrane, is heat labile, and can be precipitated by ammonium sulphate. 7. The advantages of the organism's itself inactivating acrasin are considered. 8. Some of the advantages of a source's releasing acrasin in pulses are discussed; but it is not essential for orientation for it to do so. 9. Sensitive amoebae not only are oriented by an acrasin solution but are caused to secrete acrasin: this is the basis of a chemotactic relay system.

A Synthetic Method for Site‐Specific Functionalized Polypeptides: Metal‐Free, Highly Active, and Selective at Room Temperature

2020 ◽  
Vol 60 (2) ◽  
pp. 889-895
Author(s):  
Wei Zhao ◽  
Yanfeng Lv ◽  
Ji Li ◽  
Zihao Feng ◽  
Yonghao Ni ◽  
...  
Keyword(s):  
Room Temperature ◽  
Synthetic Method ◽  
Site Specific ◽  
Metal Free ◽  
Highly Active

scholarly journals The synthesis of highly active carbon dot-coated gold nanoparticles via the room-temperature in situ carbonization of organic ligands for 4-nitrophenol reduction

RSC Advances ◽  
2020 ◽  
Vol 10 (33) ◽  
pp. 19419-19424
Author(s):  
Yue Zhu ◽  
Juan Du ◽  
Qianqian Peng ◽  
Fengyi Wang ◽  
Jing Hu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Active Carbon ◽  
Room Temperature ◽  
Organic Ligands ◽  
Carbon Dot ◽  
Highly Active ◽  
Nitrophenol Reduction ◽  
In Situ Carbonization

Due to the serious pollution issue caused by 4-nitrophenol (4-NP), it is of great importance to design effective catalysts for its reduction.

Hydrophosphination of alkenes and alkynes with primary phosphines catalyzed by zirconium complexes bearing aminophenolato ligands

2018 ◽  
Vol 47 (27) ◽  
pp. 9090-9095 ◽  
Author(s):  
Yu Zhang ◽  
Xinxin Wang ◽  
Yaorong Wang ◽  
Dan Yuan ◽  
Yingming Yao
Keyword(s):  
Room Temperature ◽  
Highly Active ◽  
Zirconium Complexes

Zirconium complexes supported by amine-bridged bis(phenolato) ligands have been developed as highly active and chemo-selective catalysts in hydrophosphination of alkenes and alkynes with primary phosphines at room temperature.

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