scholarly journals Palladium PEPPSI-IPr Complex Supported on a Calix[8]arene: A New Catalyst for Efficient Suzuki–Miyaura Coupling of Aryl Chlorides

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1081
Author(s):  
Axel Labattut ◽  
Ibrahim Abdellah ◽  
Julien Buendia ◽  
Sandra Abi Fayssal ◽  
Erika Adhel ◽  
...  
Keyword(s):  
Steric Hindrance ◽  
High Reactivity ◽  
Synthesis And Characterization ◽  
Metal Leaching ◽  
Great Promise ◽  
Aryl Chlorides ◽  
Mild Conditions ◽  
Rare Combination

We report here the synthesis and characterization of a new calix[8]arene-supported PEPPSI-IPr Pd polymetallic complex. This complex, showing greater steric hindrance around the Pd centers compared with previous calix[8]arene-based catalysts, demonstrated high reactivity and selectivity for the Suzuki–Miyaura coupling of aryl chlorides under mild conditions. Along with this good performance, the new catalyst showed low Pd leaching into the final Suzuki–Miyaura coupling products, indicative of a heterogeneous-type reactivity. This rare combination of good reactivity towards challenging substrates and low metal leaching offers great promise at both academic and industrial levels.

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>

Synthesis and Characterization of a New Coumarin-1,2,3-Triazole Diad

2014 ◽  
Vol 618 ◽  
pp. 170-174
Author(s):  
Hong Qi Li ◽  
Xiu Juan Tian ◽  
Zhen Chen ◽  
Ding Xiao ◽  
Ning Fang ◽  
...  
Keyword(s):  
Click Chemistry ◽  
Biological Activities ◽  
Antitubercular Activity ◽  
Synthesis And Characterization ◽  
Target Compound ◽  
H Nmr ◽  
Mild Conditions ◽  
Ideal Approach ◽  
C Nmr

A new coumarin-1,2,3-triazole diad was designed and synthesized by Pechmann-Duisberg reaction and click chemistry. The three-step synthetic route to the target compound afforded an overall yield of 56%. The structures of the synthesized compounds were characterized by 1H NMR, 13C NMR, IR and mass spectrum. The click chemistry provided an ideal approach for synthesis under mild conditions of coumarin-1,2,3-triazole diads which may exhibit excellent biological activities such as antitubercular activity.

Synthesis and characterization of photoelectrochemical and photovoltaic Cu2BaSnS4 thin films and solar cells

2017 ◽  
Vol 5 (26) ◽  
pp. 6406-6419 ◽  
Author(s):  
Jie Ge ◽  
Yanfa Yan
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Water Splitting ◽  
Photoelectrochemical Water Splitting ◽  
Synthesis And Characterization ◽  
Great Promise ◽  
Solar Absorbers ◽  
Earth Abundant ◽  
Photovoltaic Solar Cells

Earth abundant Cu2BaSnS4 thin films hold great promise for use as solar absorbers in the photoelectrochemical water splitting and the top cell of tandem photovoltaic solar cells.

scholarly journals Electrophilic oligodeoxynucleotide synthesis using dM-Dmoc for amino protection

2019 ◽  
Vol 15 ◽  
pp. 1116-1128 ◽  
Author(s):  
Shahien Shahsavari ◽  
Dhananjani N A M Eriyagama ◽  
Bhaskar Halami ◽  
Vagarshak Begoyan ◽  
Marina Tanasova ◽  
...  
Keyword(s):  
Michael Addition ◽  
Steric Hindrance ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Side Product ◽  
Synthesis And Characterization ◽  
Protecting Group ◽  
Phase Synthesis ◽  
Improved Technology

Solid-phase synthesis of electrophilic oligodeoxynucleotides (ODNs) was achieved using dimethyl-Dmoc (dM-Dmoc) as amino protecting group. Due to the high steric hindrance of the 2-(propan-2-ylidene)-1,3-dithiane side product from deprotection, the use of excess nucleophilic scavengers such as aniline to prevent Michael addition of the side product to the deprotected ODN during ODN cleavage and deprotection was no longer needed. The improved technology was demonstrated by the synthesis and characterization of five ODNs including three modified ones. The modified ODNs contained the electrophilic groups ethyl ester, α-chloroamide, and thioester. Using the technology, the sensitive groups can be installed at any location within the ODN sequences without using any sequence- or functionality-specific conditions and procedures.

Synthesis and characterization of Zn2GeO4/Mg-MOF-74 composites with enhanced photocatalytic activity for CO2 reduction

2018 ◽  
Vol 8 (5) ◽  
pp. 1288-1295 ◽  
Author(s):  
Hui Zhao ◽  
Xusheng Wang ◽  
Jifei Feng ◽  
Yanning Chen ◽  
Xue Yang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Co2 Reduction ◽  
Synthesis And Characterization ◽  
Mild Conditions

Zn2GeO4/Mg-MOF-74 composites are explored for artificial CO2 phototransformation under mild conditions.

Synthesis and Characterization of Triazole-Linked Bistetrahydrobenzofuran Derivatives as Anti-Ulcer Agents

2014 ◽  
Vol 997 ◽  
pp. 128-131
Author(s):  
Quan Li Yang ◽  
Chun Xue Chen ◽  
Wu Li ◽  
Wan Liu ◽  
Hu Biao Fang ◽  
...  
Keyword(s):  
Elemental Analysis ◽  
Click Reaction ◽  
Bioactive Compound ◽  
Inhibitory Effect ◽  
Synthesis And Characterization ◽  
Mild Conditions ◽  
Inhibitory Activities ◽  
High Yields

A pair of triazole-linked bistetrahydrobenzofuran derivatives were prepared in high yields through Cu (II)-catalyzed click reaction under mild conditions. All of the intermediates and target compounds were characterized by NMR, IR, ESI-MS and elemental analysis. Thein vitroH+/K+-ATPase inhibitory effect for the target compounds were also evaluated by MTT methods, and the (E)-isomer of the bistetrahydrobenzofurans exhibited the better H+/K+-ATPase inhibitory activities than the commercial omeprazole with the IC50of 37.90 μM. The bioactive compound might be potentially used as anti-ulcer agents in the treatment of acid-related diseases.

SYNTHESIS AND CHARACTERIZATION OF FeRh NANOPARTICLES

2007 ◽  
Vol 21 (18) ◽  
pp. 1153-1159 ◽  
Author(s):  
DIANA CIUCULESCU ◽  
CATHERINE AMIENS ◽  
MARC RESPAUD ◽  
PIERRE LECANTE ◽  
ANDREA FALQUI ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Quantum Interference ◽  
Hydrogen Pressure ◽  
Mossbauer Spectroscopy ◽  
Synthesis And Characterization ◽  
Superconducting Quantum Interference Device ◽  
Mild Conditions ◽  
Mößbauer Spectroscopy ◽  
Average Size

Fe 0.8 Rh 0.2 nanoparticles with an average size of 1.8 nm have been synthesized by simultaneous decomposition of stoichiometric quantities of Fe[N(Si(CH 3)3)2]2 and Rh(C 3 H 5)3 in mild conditions of temperature and hydrogen pressure, using hexadecylamine as stabilizer. These nanoparticles display a magnetization of 1.13 μ B per iron atom, which is more than two times smaller than the bulk value with the same composition. No surface contamination with iron oxides was detected by Mössbauer spectroscopy. Superconducting quantum interference device and Mössbauer spectroscopy investigations reveal that the origin of this variation may be a core-shell Rh/Fe chemical arrangement.

Synthesis and characterization of branched copolysilanes of high molecular weight with high steric hindrance

2002 ◽  
Vol 38 (8) ◽  
pp. 1635-1643 ◽  
Author(s):  
Zhijian Peng ◽  
Wenjie Si ◽  
Shiwei Lin ◽  
Hezhuo Miao ◽  
Hejian Fu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Steric Hindrance ◽  
Synthesis And Characterization
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