The regiodivergent palladium-catalyzed C-H arylation of pyrazolo[1,5-a]pyrimidine has been achieved, wherein the switch in regioselectivity between positions C3 and C7 is under complete catalyst control. A phosphine-containing palladium catalyst promotes the direct arylation at the most acidic position (C7), whereas a phosphine-free catalyst targets the most electron-rich position (C3).
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http://dx.doi.org/10.1002/anie.201502150 | DOI Listing |
Molecules
January 2025
School of Metallurgical and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China.
Isoindigo (IID)-based non-fullerene acceptors, known for their broad absorption spectra and high charge carrier mobilities, play a crucial role in organic photovoltaics. In this study, two A-DA'D-A type unfused ring acceptors (URAs), IDC8CP-IC and IDC6CP-IC, were designed and synthesized using cyclopentadithiophene (CPDT) and IID core units, each functionalized with different alkyl chains (2-hexyldecyl and 2-octyldodecyl), through an atom- and step-efficient direct C-H arylation (DACH) method. Both URAs, despite the absence of non-covalent conformation locking between CPDT and IID, demonstrated favorable molecular planarity, broad absorption ranges, low band gaps, and high molar absorption coefficients.
View Article and Find Full Text PDFSci Adv
January 2025
State Key Laboratory of Organometallic Chemistry and Shanghai Hongkong Joint Laboratory in Chemical Synthesis, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 (China).
Singly occupied molecular orbital (SOMO) activation of in situ generated enamines has achieved great success in (asymmetric) α-functionalization of carbonyl compounds. However, examples on the use of this activation mode in the transformations of other functional groups are rare, and the combination of SOMO activation with transition metal catalysis is still less explored. In the area of deoxygenative functionalization of amides, intermediates such as iminium ions and enamines were often generated in situ to result in the formation of α-functionalized amines.
View Article and Find Full Text PDFMolecules
January 2025
Sustainable Chemistry for Metals and Molecules, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium.
A pyridine-fused triazapentalene shows weak fluorescence in solution and is readily accessible via nitrene-mediated cyclization. In this study, a modified Cadogan reaction was used to synthesize . Palladium-catalyzed reactions have been used as post-functionalization methods.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States.
Monoanionic, bidentate-auxiliary-directed, cobalt-catalyzed C-H bond functionalization has become a very useful tool in organic synthesis. A comprehensive investigation into isolated organometallic intermediates and their reactivity within the catalytic cycle is lacking. We report here mechanistic studies of cobalt-catalyzed, aminoquinoline-directed C(sp)-H bond functionalization.
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.
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