Copper(II)-mediated C-H oxidation is the subject of extensive interest in synthetic chemistry, but the mechanisms of many of these reactions are poorly understood. Here, we observe different products from Cu(II)-mediated oxidation of N-(8-quinolinyl)benzamide, depending on the reaction conditions. Under basic conditions, the benzamide group undergoes directed C-H methoxylation or chlorination. Under acidic conditions, the quinoline group undergoes nondirected chlorination. Experimental and computational mechanistic studies implicate an organometallic C-H activation/functionalization mechanism under the former conditions and a single-electron-transfer mechanism under the latter conditions. This rare observation of divergent, condition-dependent mechanisms for oxidation of a single substrate provides a valuable foundation for understanding Cu(II)-mediated C-H oxidation reactions.
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http://dx.doi.org/10.1021/ja4026424 | DOI Listing |
J Org Chem
January 2025
Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur 302017, Rajasthan, India.
J Am Chem Soc
January 2025
Department of Chemistry, University of Texas at Austin, Austin 78712, Texas, United States.
Org Lett
January 2025
School of Chemistry and Materials Science, Jiangsu Key Laboratory of Green Synthesis for Functional Materials, Jiangsu Normal University, Xuzhou, Jiangsu 221116, China.
Herein, we present a Pd(OAc)/Dppp-catalyzed synthesis of 4-arylphenanthridinones from 2-bromobenzamides and iodobenzene, which undergoes successive Ullman cross-coupling, C-H activation, and oxidative coupling dehydrogenation process. The presented methods offer an adaptable and modular synthesis route for efficiently producing a wide array of valuable phenanthridiones, demonstrating exceptional compatibility with functional groups. Alternatively, a 1:1 cross-coupling reaction utilizing an intramolecular norbornene moiety as the ligand resulted in phenanthridinones through -arylation and C-H activation.
View Article and Find Full Text PDFDalton Trans
January 2025
Phosphorus Laboratory, Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Phosphole and azaphosphole derivatives with triazole functionalities, [CH{1,2,3-NCCHC(PPh)}] (L1) and [CH{1,2,3-NC(Ph)C(PPh)}] (L2) were synthesized by reacting [(CH)(1,2,3-NC = CH--Br-CH)] and [(-Br-CH)(1,2,3-NC = CHCH)] with BuLi followed by the addition of dichlorophenylphosphine. The reactions of L1 and L2 with an excess of 30% HO afforded phosphole oxides [CH{1,2,3-NCCHC(P(O)Ph)}] (L1O) and [CH{1,2,3-NC(Ph)C(P(O)Ph)}] (L2O) as white crystalline solids. Stoichiometric reactions of L1 and L2 with [Ru(η--cymene)Cl] in CHCl yielded [RuCl(η--cymene)(L1-κ-)] (1) and [RuCl(η--cymene)(L2-κ-)] (2), respectively.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China.
The integration of ligand-to-metal charge transfer (LMCT) catalytic paradigms with radical intermediates has transformed the selective functionalization of inert C-H bonds, facilitating the use of nonprecious metal catalysts in demanding transformations. Notably, aerobic C-H carbonylation of methane to acetic acid remains formidable due to the rapid oxidation of methyl radicals, producing undesired C1 oxygenates. We present an iron terpyridine catalyst utilizing LMCT to achieve exceptional C2/C1 selectivity through synergistic photoexcitation, methyl radical generation, and carbonylation.
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