This paper describes a new palladium-catalyzed method for C-H activation/carbon-carbon bond formation with hypervalent iodine arylating agents. This transformation has been applied to a variety of arene and benzylic substrates containing different directing groups (pyridines, quinolines, oxazolidinones, and amides) and proceeds with high levels of regiocontrol. Mechanistic experiments provide preliminary evidence in support of an unusual mechanism for this transformation involving a Pd(II)/Pd(IV) catalytic cycle.
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Nat Commun
January 2025
Key Laboratory of advanced catalysis, College of Chemistry and Chemical Engineering, Lanzhou University, 730000, Lanzhou, China.
Compared to the sluggish kinetics observed in methanol-mediated side-chain alkylation of methyl groups with sp C-H bonds, CO hydrogenation emerges as a sustainable alternative strategy, yet it remains a challenge. Here, as far as we know, it is first reported that using CO hydrogenation replacing methanol can conduct the side-chain alkylation of 4-methylpyridine (MEPY) over a binary metal oxide-zeolite ZnZrO/CsX tandem catalyst (ZZO/CsX). This ZZO/CsX catalyst can achieve 19.
View Article and Find Full Text PDFJ Org Chem
January 2025
School of Chemistry and Materials Science, Jiangsu Key Laboratory of Green Synthesis for Functional Materials, Jiangsu Normal University, Xuzhou, Jiangsu 221116, China.
The Ullmann coupling and oxidative coupling dehydrogenation reactions have occurred sequentially, catalyzed by Pd(OAc), which unexpectedly yielded fused imidazo[1,2-]phenanthridine derivatives in good to high yields. Structural analysis of the intermediate and final products indicated that the protocol did not include C-H and N-H arylation.
View Article and Find Full Text PDFFront Chem
December 2024
Department of Chemistry, University of Lucknow, Lucknow, India.
Rhodium(III) catalysis has been used for C-H activation of -nitrosoanilines with substituted allyl alcohols. This method provides an efficient synthesis of the functional -nitroso β-aryl aldehydes and ketones with low catalyst loading, high functional group tolerance, and superior reactivity of allyl alcohols toward -nitrosoanilines. We demonstrated that reaction also proceeds through the one-pot synthesis of -nitrosoaniline, followed by subsequent, C-H activation.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of California, Berkeley, California 94720, United States.
Dioxygen (O) is a potent oxidant used by aerobic organisms for energy transduction and critical biosynthetic processes. Numerous metalloenzymes harness O to mediate C-H bond hydroxylation reactions, but most commonly feature iron or copper ions in their active site cofactors. In contrast, many manganese-activated enzymes─such as glutamine synthetase and isocitrate lyase─perform redox neutral chemical transformations and very few are known to activate O or C-H bonds.
View Article and Find Full Text PDFOrg Lett
December 2024
Division of Medicinal Chemistry, CSIR-Institute of Microbial Technology, Chandigarh 160036, India.
A novel palladium-catalyzed intramolecular C-H amination via oxidative coupling exploiting inactivated N-substituted aryl amines on indoles for the one-pot synthesis of novel 11-benzo[4,5]imidazo[1,2-]indole derivatives is reported. The optimized reaction conditions accommodated a wide range of electronic variations on both the indole and the pendant aryl amine ring, resulting in products with good to excellent yields.
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