In this work we analyze the whole molecular mechanism for intramolecular aromatic hydroxylation through O2 activation by a Schiff hexaazamacrocyclic dicopper(I) complex, [Cu(I) 2(bsH2m)](2+). Assisted by DFT calculations, we unravel the reaction pathway for the overall intramolecular aromatic hydroxylation, i.e., from the initial O2 reaction with the dicopper(I) species to first form a Cu(I)Cu(II)-superoxo species, the subsequent reaction with the second Cu(I) center to form a μ-η(2):η(2)-peroxo-Cu(II) 2 intermediate, the concerted peroxide O-O bond cleavage and C-O bond formation, followed finally by a proton transfer to an alpha aromatic carbon that immediately yields the product [Cu(II) 2(bsH2m-O)(μ-OH)](2+).
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http://dx.doi.org/10.3762/bjoc.9.63 | DOI Listing |
Chemistry
January 2025
Yamaguchi University, Department of Chemistry, 753-8512, Yamaguchi, JAPAN.
We report herein the synthesis of an unprecedented isomer of perylene, dicyclohepta[cd,fg]-as-indacene bearing two phenyl groups (1-Ph) by the nickel-mediated intramolecular homocoupling of a 4,4'-biazulene derivative (2). The X-ray crystallographic analysis and theoretical calculations revealed that 1-Ph adopts a unique helically twisted geometry although the local aromaticity of azulene moieties was preserved. The double covalent linkage of the two azulene skeletons imparts significant orbital interaction, which affords near-infrared (NIR) absorption (up to 1720 nm) and remarkable redox behaviors despite its closed-shell electronic structure.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Okayama Daigaku Daigakuin Shizen Kagaku Kenkyuka, Division of Applied Chemistry, JAPAN.
Intramolecular aromatic oxidative coupling of 3,6-bis(m-terphenyl-2'-yl)carbazole provided a bis(m-terphenyl)-fused carbazole, while that of 3,6-bis(m-terphenyl-2'-yl)-1,8-diphenylcarbazole afforded a bis(quaterphenyl)-fused carbazole. Borylation of the latter furnished a B,N-embedded helical nanographene binding a fluoride anion via a structural change from the three-coordinate boron to the four-coordinate boron. The anionic charge derived from the fluoride anion is stabilized over the expanded p-framework, which leads to the high binding constant (Ka) of 1 × 105 M-1.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou 325035, P. R. China.
Herein, we developed a silane-promoted cycloaddition of thiobenzhydrazides with carbon dioxide leading to 1,3,4-thiadiazol-2(3)-ones. This procedure involves sequential -silylation and fixation of carbon dioxide toward a hydrazine formyl intermediate, followed by intramolecular nucleophilic cyclization and aromatization. A series of functional groups are well-tolerated under this procedure.
View Article and Find Full Text PDFJ Org Chem
January 2025
State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
2-Hydroxyl/acetoxy-3-nitroindoles are directly and efficiently prepared in good to excellent yields from diazo(nitro)acetanilides under the catalysis of Cu(MeCN)PF in DCM through an intramolecular aromatic C-H insertion or followed by acetylation. 2-Hydroxyl-3-nitroindoles can be further transformed to 3-halo-3-nitroindolin-2-ones and 3-alkanamidoindolin-2-ones readily. All of them are important synthetic building blocks for construction of indole derivatives.
View Article and Find Full Text PDFMolecules
December 2024
Department of Chemical and Materials Engineering, Lyuliang University, Lishi 033001, China.
We studied the boron-based composite cluster BAl doped with Al atoms. The global minimum structure of the BAl cluster is a three-layer structure, consisting of three parts: an Al unit, a B ring and an isolated Al atom. Charge calculations analysis shows that the cluster can be expressed as [Al][B][Al], has 6π/6σ double aromaticity and follows the (4+2) Hückel rule.
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