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Enantioconvergent catalysis enables the conversion of racemic molecules into a single enantiomer in perfect yield and is considered an ideal approach for asymmetric synthesis. Despite remarkable advances in this field, enantioconvergent transformations of inert tertiary C-H bonds remain largely unexplored due to the high bond dissociation energy and the surrounding steric repulsion that pose unparalleled constraints on bond cleavage and formation. Here, we report an enantioconvergent Pd-catalyzed alkylation of racemic tertiary allylic C-H bonds of α-alkenes, providing a unique approach to access a broad range of enantioenriched γ,δ-unsaturated carbonyl compounds featuring quaternary carbon stereocenters. Mechanistic studies reveal that a stereoablative event occurs through the rate-limiting cleavage of tertiary allylic C-H bonds to generate σ-allyl-Pd species, and the achieved E/Z-selectivity of σ-allyl-Pd species effectively regulates the diastereoselectivity via a nucleophile coordination-enabled S 2'-allylation pathway.
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http://dx.doi.org/10.1002/anie.202312547 | DOI Listing |
J Phys Chem A
September 2025
Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States.
Ionization of alkanes to form radical cations activates their otherwise unreactive C-H bonds, facilitating important chemical processes such as hydrocarbon cracking. This work investigates the radical cation dissociation dynamics of hexane (CH) structural isomers by using femtosecond time-resolved mass spectrometry and quantum chemical calculations. All five isomers exhibit competition between the yields of fragment ions arising from direct C-C bond cleavage or dissociative rearrangement with hydrogen migration on dynamical time scales of ∼50-300 fs, suggesting that hydrogen migration in the metastable cations operates on such short time scales.
View Article and Find Full Text PDFInorg Chem
September 2025
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Molecular Sciences, Henan University, Kaifeng, Henan 475004, China.
Selective oxidation of benzylic C(sp)-H bonds to ketones is critical to the production of fine chemicals but typically requires toxic/precious metal catalysts under harsh conditions. While iron-based complexes have recently served as catalysts for photocatalytic C-H bond activation, most systems operate via homogeneous catalysis. Developing a light-driven strategy under visible light with O as an oxidant is of major importance.
View Article and Find Full Text PDFOrg Lett
September 2025
Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Allenes have gained prominence in transition metal-catalyzed C-H activation reactions due to their versatile reactivity. While C(sp)-H functionalization with allenes has been well explored, the functionalization of more challenging C(sp)-H bonds with allenes remains largely underexplored. Herein, we present a scalable Rh(III)-catalyzed strategy for the site-selective C(sp)-H dienylation of biologically relevant 8-methylquinolines employing allenyl carbinol acetates for accessing structurally diverse 1,3-dienes.
View Article and Find Full Text PDFChem Commun (Camb)
September 2025
Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, CH-3012 Bern, Switzerland.
Iron complexes bearing chiral salicyloxazoline (Salox) ligands catalyze the enantioselective intramolecular C-H bond amination of alkyl azides, reaching 58-76% ee for benzylic C-H bonds. Further, for the first time aliphatic C-H bond amination is demonstrated (∼40% ee). This class of catalysts even activates primary aliphatic C-H bonds, albeit with moderate ee.
View Article and Find Full Text PDFChem Sci
August 2025
College of Chemistry and Chemical Engineering, Jiangxi Province Engineering Research Center of Ecological Chemical Industry, Jiujiang University Jiujiang 332005 China
BN-fused aromatic compounds have garnered significant attention due to their unique electronic structures and exceptional photophysical properties, positioning them as highly promising candidates for applications in organic optoelectronics. However, the regioselective synthesis of BN isomers remains a formidable challenge, primarily stemming from the difficulty in precisely controlling reaction sites, limiting structural diversity and property tunability. Herein, we propose a regioselective synthetic strategy that employs 2,1-BN-naphthalene derivatives, wherein selective activation of N-H and C-H bonds is achieved in conjunction with -halogenated phenylboronic acids.
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