A detailed mechanism for alkyne alkoxycarbonylation mediated by a palladium catalyst has been characterised at the B3PW91-D3/PCM level of density functional theory (including bulk solvation and dispersion corrections). This transformation, investigated via the methoxycarbonylation of propyne, involves a uniquely dual role for the P,N hemilabile ligand acting co-catalytically as both an in situ base and proton relay coupled with a Pd(0) centre, allowing for surmountable barriers (highest ΔG(≠) of 22.9 kcal mol(-1) for alcoholysis). This proton-shuffle between methanol and coordinated propyne accounts for experimental requirements (high acid concentration) and reproduces observed regioselectivities as a function of ligand structure. A simple ligand modification is proposed, which is predicted to improve catalytic turnover by three orders of magnitude.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/chem.201403983 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Bioorthogonal chemical reporters for profiling retinoic acid-modified and retinoic acid-interacting proteins.
Bioorg Med Chem
January 2025
State Key Laboratory of Chemical Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China. Electronic address:
Vitamin A and its primary active derivative, all-trans retinoic acid (RA), are endogenous signaling molecules essential for numerous biological processes, including cell proliferation, differentiation, and immune modulation. Owing to its differentiation-inducing effect, RA was the first differentiating agent approved for the clinical treatment of acute myeloid leukemia. While the classical mechanisms of RA signaling involve nuclear receptors, such as retinoic acid receptors (RARs), emerging evidence suggests that RA also engages in non-covalent and covalent interactions with a broader range of proteins.
View Article and Find Full Text PDFDiscovery, Characterization, and Anti-XOD Activity of Calcium Metallophore from .
Org Lett
January 2025
School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.
In this work, coixalkyne A (), a natural polynuclear calcium complex with a novel cross-shaped molecular architecture, was isolated from L. along with the undescribed analogue coixalkyne B (). Their structures were identified by means of NMR spectroscopy, ECD calculations, and single-crystal X-ray diffraction.
View Article and Find Full Text PDFMo(0) carbonyl complexes bearing the bis(3,5-dimethylpyrazole) ligand: catalysis of the regioselective [2 + 2 + 2] cycloaddition of terminal alkynes to synthesize 1,3,5-isomers.
Dalton Trans
January 2025
Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, 721302 India.
The reaction between 1,3-bis(3,5-dimethylpyrazolylmethyl)hexahydropyrimidine L and Mo(CO) in CHCN at 130 °C afforded a binuclear Mo(0) complex 1 containing a new macrocycle formed upon C-N bond cleavage in L in good yield. Conversely, a clean reaction takes place between L and [Mo(CO)(COD)] in THF at 60 °C to give a new metalloligand complex [Mo(CO)(κ-,-L)] 2 containing a spectator pyrazole arm in 83% yield. Their structures were determined by X-ray diffraction methods, and a plausible mechanism is proposed for the C-N bond cleavage leading to complex 1.
View Article and Find Full Text PDFCobalt-Catalyzed Enantioselective Reductive Coupling of Imines and Internal Alkynes.
Angew Chem Int Ed Engl
January 2025
IISER Kolkata: Indian Institute of Science Education and Research Kolkata, Department of Chemical Sciences, Mohanpur, 741246, Nadia, INDIA.
Chiral allyl amines are important structural components in natural products, pharmaceuticals, and chiral catalysts. Herein, we report a cobalt-catalyzed enantioselective reductive coupling of imines with internal alkynes to synthesize chiral allyl amines. The reaction is catalyzed by a cobalt complex derived from commercially available bisphosphine ligand utilizing zinc as the electron donor.
View Article and Find Full Text PDFBoosting Electrocatalytic Hydrogenation of Phenylacetylene via Accelerating Water Electrolysis on a Cr-CuO Surface.
ACS Appl Mater Interfaces
January 2025
Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Guizhou University, Guiyang, Guizhou 550025, China.
Electrochemical alkyne reduction with HO as a hydrogen source represents a sustainable route for value-added olefin production. However, the reaction efficiency is hampered by the high voltage and low activity of Cu electrodes due to their weak adsorbed hydrogen (*H) generation property. In this article, we present the enhanced electrocatalysis of phenylacetylene to styrene over a highly dispersive Cr-doped CuO nanowire (Cr-CuO) cathode.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!