The rational design of a phosphine ligand for the reductive elimination-demanding Pd-catalyzed mono-α-arylation of acetone is demonstrated and reported. The catalyst is tolerant of previously proven challenging electron-deficient aryl chlorides and provides excellent product yields with down to 0.1 mol % Pd. Preliminary investigations suggest that the rate-limiting step for the proposed system is the oxidative addition of aryl chlorides, in which it contradicts previous findings regarding the α-arylation of acetone with aryl halides.
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http://dx.doi.org/10.1021/acs.orglett.5b02344 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, University of Wisconsin─Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Aryl triflates make up a class of aryl electrophiles that are available in a single step from the corresponding phenol. Despite the known reactivity of nickel complexes for aryl C-O bond activation of phenol derivatives, nickel-catalyzed cross-electrophile coupling using aryl triflates has proven challenging. Herein, we report a method to form C(sp)-C(sp) bonds by coupling aryl triflates with alkyl bromides and chlorides using phenanthroline (phen) or pyridine-2,6-bis(-cyanocarboxamidine) (PyBCam)-ligated nickel catalysts.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
The C2- or C3-selective direct C-H arylation of nonsubstituted 1-pyrrole with aryl chlorides/nonaflates was achieved using catalysts derived from palladium and appropriate phosphine ligands. The site selectivity of the arylation can be switched by changing the ligands, and the C3-selective arylation of nonsubstituted 1-pyrrole was realized for the first time. BuOLi played an important role in suppressing N-arylation and accelerating C2- or C3-arylation.
View Article and Find Full Text PDFDalton Trans
January 2025
Departamento de Química Inorgánica, Universidad de Sevilla, 41012 Sevilla, Spain.
Preformed Ni(0) complexes are rarely used as precatalysts in cross-coupling reactions, although they can incorporate catalytically active nickel directly into the reaction. In this work, we focus on the preparation and the catalytic application of low-coordinate Ni(0) complexes supported by bulky monophosphine ligands in C-S cross-coupling reactions. We have prepared two families of Ni(0) complexes, bis-phosphine aducts of the type [Ni(PRAr')] (Ar' = -terphenyl group) and monophosphine derivatives of the type [Ni(PRAr')(DVDS)] (DVDS = divinyltetramethyldisiloxane).
View Article and Find Full Text PDFACS Catal
January 2025
Institute of Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg, 1, 8093 Zurich, Switzerland.
Buchwald-Hartwig (BH) aminations are crucial for synthesizing arylamine motifs in numerous bioactive molecules and fine chemicals. While homogeneous palladium complexes can be effective catalysts, their high costs and environmental impact motivate the search for alternative approaches. Heterogeneous palladium single-atom catalysts (SAC) offer promising recoverable alternatives in C-C cross-couplings.
View Article and Find Full Text PDFOrg Lett
January 2025
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, and School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China.
Carbonylation of aryl electrophiles is an important method for constructing aromatic carbonyl compounds for materials science and pharmaceutical applications. However, there have been few studies on the carbonylation of abundant, inexpensive aryl chlorides. Moreover, the existing carbonylation methods usually require a high temperature, control of the CO pressure, and structurally complex catalysts and ligands.
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