Density functional theory (DFT) calculations have been performed to investigate the oxidation of alcohol to acetaldehyde, catalyzed by the (bpy)Cu(I)-TEMPO/NMI catalytic system. Three pathways (path A, path B and path C) are presented. Our calculations indicate that path B is the favourable pathway. In path B, the alcohol coordinating to the Cu(I) center provides a H atom to TEMPO to form TEMPOH. Another TEMPO then replaces TEMPOH to abstract the H atom from the Cα-H of the alcoholate (RCH2O(-)) to generate the aldehyde product. On the basis of the studied pathway, a possible mechanism is presented to explain the experimental observations.
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http://dx.doi.org/10.1039/c4dt03051f | DOI Listing |
Sci Rep
July 2024
Center of Excellence for Innovation in Chemistry (PERCH-CIC), Department of Chemistry, Faculty of Science, Mahidol University, Bangkok, Thailand.
We synthesized a class of ligands that feature single (L1) and dual amine-bis(triazole) chelates (L2 with a 1,3-phenylene linker and L3 with a 1,5-naphthalene linker). Our findings which were derived from UV-Vis titrations, crystal structure analysis of relevant copper complexes, and DFT calculations indicate the formation of both mononuclear CuBr(L1) and dinuclear (μ-Ln)(CuBr) (Ln = L2 and L3) complexes. The catalytic activities of CuBr/Ln, in combination with TEMPO (2,2,6,6-tetramethylpiperidin-1-yl)oxyl) co-catalyst and NMI (N-methylimidazole) for aerobic alcohol oxidation, reveal the following activity trend: CuBr/L3 > CuBr/L2 > CuBr/L1.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
April 2024
School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science (IACS), 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India.
In biological systems, programmable supramolecular frameworks characterized by coordinated directional non-covalent interactions are widespread. However, only a small number of reports involve pure water-based dynamic supramolecular assembly of artificial π-amphiphiles, primarily due to the formidable challenge of counteracting the strong hydrophobic dominance of the π-surface in water, leading to undesired kinetic traps. This study reveals the pathway complexity in hydrogen-bonding-mediated supramolecular polymerization of an amide-functionalized naphthalene monoimide (NMI) building block with a hydrophilic oligo-oxyethylene (OE) wedge.
View Article and Find Full Text PDFInorg Chem
November 2022
Department of Chemistry, Indian Institute of Technology Jammu Jagti, Jammu 181221, India.
A series of azo-aromatic copper(II) complexes, [] and a Cu(I) complex, [], with varying amine-functionalized hemilabile pincer-like [] and [], methyl-substituted azo [], and imine [] ligands, were synthesized and characterized. These complexes were investigated for aerobic oxidation of a variety of aromatic alcohols in the presence of 2.0 mol % precatalysts [], cobaltocene (2.
View Article and Find Full Text PDFAcc Chem Res
September 2022
Asymmetric organocatalysis has been considered to be an efficient and reliable strategy for the stereoselective preparation of optically active chemicals. In particular, chiral tertiary amines as Lewis base organocatalysts bearing core structures including quinuclidine, dimethylaminopyridine (DMAP), -methylimidazole (NMI), amidine, etc. have provided new and powerful tools for various chemical transformations.
View Article and Find Full Text PDFComput Struct Biotechnol J
May 2022
Faculty of Science, University of South Bohemia in České Budějovice, Branišovská 1760, České Budějovice 370 05, Czech Republic.
Tick-borne encephalitis virus (TBEV), the most medically relevant tick-transmitted flavivirus in Eurasia, targets the host central nervous system and frequently causes severe encephalitis. The severity of TBEV-induced neuropathogenesis is highly cell-type specific and the exact mechanism responsible for such differences has not been fully described yet. Thus, we performed a comprehensive analysis of alterations in host poly-(A)/miRNA/lncRNA expression upon TBEV infection in human primary neurons (high cytopathic effect) and astrocytes (low cytopathic effect).
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