Efficient C−H/C−D Exchange Reaction on the Alkyl Side Chain of Aromatic Compounds Using Heterogeneous Pd/C in D2O

2004 ◽  
Vol 6 (9) ◽  
pp. 1485-1487 ◽  
Author(s):  
Hironao Sajiki ◽  
Fumiyo Aoki ◽  
Hiroyoshi Esaki ◽  
Tomohiro Maegawa ◽  
Kosaku Hirota
Keyword(s):  
Exchange Reaction ◽  
Aromatic Compounds ◽  
Side Chain ◽  
Alkyl Side Chain

scholarly journals Production of Aromatic Compounds by Catalytic Depolymerization of Technical and Downstream Biorefinery Lignins

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1338 ◽  
Author(s):  
Alfonso Cornejo ◽  
Fernando Bimbela ◽  
Rui Moreira ◽  
Karina Hablich ◽  
Íñigo García-Yoldi ◽  
...  
Keyword(s):  
Aromatic Compounds ◽  
Quantum Coherence ◽  
Base Catalysis ◽  
Industrial Wastes ◽  
Size Exclusion ◽  
Side Chain ◽  
Resonance Spectroscopy ◽  
Alkyl Side Chain ◽  
Alkyl Side Chains ◽  
Exclusion Chromatography

Lignocellulosic materials are promising alternatives to non-renewable fossil sources when producing aromatic compounds. Lignins from Populus salicaceae. Pinus radiata and Pinus pinaster from industrial wastes and biorefinery effluents were isolated and characterized. Lignin was depolymerized using homogenous (NaOH) and heterogeneous (Ni-, Cu- or Ni-Cu-hydrotalcites) base catalysis and catalytic hydrogenolysis using Ru/C. When homogeneous base catalyzed depolymerization (BCD) and Ru/C hydrogenolysis were combined on poplar lignin, the aromatics amount was ca. 11 wt.%. Monomer distributions changed depending on the feedstock and the reaction conditions. Aqueous NaOH produced cleavage of the alkyl side chain that was preserved when using modified hydrotalcite catalysts or Ru/C-catalyzed hydrogenolysis in ethanol. Depolymerization using hydrotalcite catalysts in ethanol produced monomers bearing carbonyl groups on the alkyl side chain. The analysis of the reaction mixtures was done by size exclusion chromatography (SEC) and diffusion ordered nuclear magnetic resonance spectroscopy (DOSY NMR). 31P NMR and heteronuclear single quantum coherence spectroscopy (HSQC) were also used in this study. The content in poly-(hydroxy)-aromatic ethers in the reaction mixtures decreased upon thermal treatments in ethanol. It was concluded that thermo-solvolysis is key in lignin depolymerization, and that the synergistic effect of Ni and Cu provided monomers with oxidized alkyl side chains.

An isomerized alkyl side chain enables efficient nonfullerene organic photovoltaics with good tolerance to pre/post-treatments

2021 ◽  
Vol 5 (7) ◽  
pp. 3050-3060 ◽  
Author(s):  
Chenyu Han ◽  
Huanxiang Jiang ◽  
Pengchao Wang ◽  
Lu Yu ◽  
Jianxiao Wang ◽  
...  
Keyword(s):  
Organic Photovoltaics ◽  
Side Chain ◽  
Alkyl Side Chain ◽  
Good Tolerance

An alkyl isomerization strategy is reported to finely modulate the crystallinity of nonfullerene acceptors as well as their photovoltaic responses to post-treatments.

scholarly journals Investigation of the Anti-Methicillin-Resistant Staphylococcus aureus Activity of (+)-Tanikolide- and (+)-Malyngolide-Based Analogues Prepared by Asymmetric Synthesis

2021 ◽  
Vol 22 (12) ◽  
pp. 6400
Author(s):  
Joseph Breheny ◽  
Cian Kingston ◽  
Robert Doran ◽  
Joao Anes ◽  
Marta Martins ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Asymmetric Synthesis ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antimicrobial Properties ◽  
Side Chain ◽  
Alkyl Side Chain ◽  
Methicillin Resistant ◽  
Antibacterial And Antifungal

Herein, we report antibacterial and antifungal evaluation of a series of previously prepared (+)-tanikolide analogues. One analogue, (4S,6S)-4-methyltanikolide, displayed promising anti-methicillin-resistant Staphylococcus aureus activity with a MIC of 12.5 µg/mL. Based on the antimicrobial properties of the structurally related (−)-malyngolide, two further analogues (4S,6S)-4-methylmalyngolide and (4R,6S)-4-methylmalyngolide bearing a shortened n-nonyl alkyl side chain were prepared in the present study using a ZrCl4-catalysed deprotection/cyclisation as the key step in their asymmetric synthesis. When these were tested for activity against anti-methicillin-resistant Staphylococcus aureus, the MIC increased to 50 µg/mL.

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