Article
Chemistry, Multidisciplinary
Oleksandr Kysliak, Simon H. F. Schreiner, Niklas Grabicki, Phil Liebing, Florian Weigend, Oliver Dumele, Robert Kretschmer
Summary: Many chemicals known today have aromaticity, which is achieved through the delocalization of pi-electrons in a ring structure. We report the synthesis of a dipotassium cyclopentagallene, a rare example of a five-membered aromatic ring stabilized by only two pi-electrons. Experimental and computational data confirm its aromatic character.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Ina Michalsky, Viktoria Gensch, Christian Walla, Marvin Hoffmann, Frank Rominger, Thomas Oeser, Petra Tegeder, Andreas Dreuw, Milan Kivala
Summary: A family of fully bridged triphenylamines with embedded 5- and 7-membered rings is presented. The compounds can undergo strong donor/acceptor interactions with strong cyano-based acceptors in both the solid state and solution.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Review
Biochemistry & Molecular Biology
Andrea Angeli, Niccolo Paoletti, Claudiu T. Supuran
Summary: The development of heterocyclic derivatives, particularly five-membered heterocyclic sulfonamides, as carbonic anhydrase inhibitors (CAIs) has been significant in the field of medicinal chemistry. Oxygen and nitrogen five-membered heterocyclic aromatic rings are important, but the installation of sulfonamide moiety on such heterocycles has not been widely studied. On the other hand, 1,3,4-thiadiazole/thiadiazoline ring-bearing sulfonamides have been extensively used in a variety of pharmaceutically important CAIs. This review focuses on the diverse biological activities and pharmacological/clinical applications of these CAIs.
Article
Chemistry, Multidisciplinary
Maciej Krzeszewski, Lukasz Dobrzycki, Andrzej L. L. Sobolewski, Michal K. Cyranski, Daniel T. T. Gryko
Summary: A saddle-shaped aza-nanographene containing a central 1,4-dihydropyrrolo[3,2-b]pyrrole (DHPP) was synthesized via a four-step pathway involving intramolecular direct arylation, the Scholl reaction, and photo-induced radical cyclization. The resulting nitrogen-embedded polycyclic aromatic hydrocarbon (PAH) possesses a unique 7-7-5-5-7-7 topology with negative Gaussian curvature and significant distortion from planarity. The absorption and fluorescence maxima of this compound are in the orange-red region, with weak emission attributed to intramolecular charge-transfer. Cyclic voltammetry measurements showed three reversible oxidation steps, with an exceptionally low first oxidation potential.
Article
Chemistry, Physical
Yutong Huo, Xiaojiao Gu, Xinde Li, Peng Jin
Summary: According to Huckel's rule, cyclic molecules are aromatic if they have 4n + 2 (n = 0, 1, 2, etc.) pi electrons. However, large cyclic rings with only 2 pi electrons are rare due to structural instability. Recent experiments discovered the largest 2 pi-aromatic ring as a five-membered Ga-5 core. Density functional theory calculations predicted several inverse-sandwich Na-2(MH)(5) and half-sandwich Ca(MH)(5) or Ca(MH)(6) (M = Al, Ga or In) structures, which exhibit aromatic characteristics, effective electron delocalization, and novel collective bonding with surrounding atoms.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Review
Chemistry, Medicinal
Fabiana Plescia, Benedetta Maggio, Giuseppe Daidone, Demetrio Raffa
Summary: The quinazolinone nucleus is an important scaffold for obtaining biologically active molecules. Fused heterocycles from natural or synthetic sources are associated with a wide range of biological activities. This review focuses on 4-(3H)-quinazolinones N-3 substituted with a five-membered heterocycle containing nitrogen, sulfur, and oxygen atoms in various combinations.
EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
(2021)
Article
Chemistry, Physical
Wu-Lin Yang, Yuan-Lin Wang, Wen Li, Bu-Ming Gu, Si-Wen Wang, Xiaoyan Luo, Bo-Xue Tian, Wei-Ping Deng
Summary: This study developed an efficient method for synthesizing 8-membered benzo[b]oxocines with high stereocontrol and yield through a sequential catalytic reaction. The chiral iridium catalyst was found to control enantioselectivity, while the chiral bifunctional squaramide catalyst controlled diastereoselectivity. The strategy was also demonstrated to be applicable for synthesizing other nitrogen heterocycles with high enantiomeric enrichment.
Review
Biochemistry & Molecular Biology
Eslam Reda El-Sawy, Ahmed Bakr Abdelwahab, Gilbert Kirsch
Summary: This review provides an up-to-date overview of the synthesis of coumarin-fused, five-membered aromatic heterocycles with one heteroatom, based on the pyrone moiety, covering the period from 1966 to 2020.
Review
Chemistry, Multidisciplinary
Rosalie S. Doerksen, Tomas Hodik, Guanyu Hu, Nancy O. Huynh, William G. Shuler, Michael J. Krische
Summary: This article summarizes ruthenium-catalyzed cycloadditions to form five-, six-, and seven-membered rings, with a focus on applications in natural product total synthesis. The content is organized by ring size and reaction type, emphasizing processes that involve the formation of at least one C-C bond. Processes involving stoichiometric ruthenium, dehydrogenative condensation-reduction, s-bond activation-initiated annulations without net reduction of bond multiplicity, and photochemically promoted ruthenium-catalyzed cycloadditions are not covered.
Article
Biochemistry & Molecular Biology
Jingmin Cui, Yan Sun, Linqing Wang, Wenqiang Tan, Zhanyong Guo
Summary: Nine chitosan derivatives with aromatic five-membered heterocycles were prepared, and the effects of different grafting methods on the biological activities of these derivatives were investigated. The structures of the compounds were characterized using FT-IR spectroscopy and NMR spectroscopy, and their antioxidant, antifungal, and antibacterial activities were tested. The experimental results showed that the chitosan derivatives exhibited strong inhibitory effects against several pathogens, as well as excellent scavenging ability against radicals. Additionally, some of the derivatives showed no toxicity to L929 cells, and their good water solubility makes them potential polymers for antifungal and antibacterial biomaterials in agriculture.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Chemistry, Physical
Thong Le Minh Pham, Thanh Khoa Phung, Ho Viet Thang
Summary: Understanding the interaction between five-membered aromatic heterocycles and Fe(1 1 0) surface is crucial for designing novel inhibitors against iron and steel corrosion. In this study, the adsorption properties and bonding mechanisms of pyrrole, furan, and thiophene on Fe(1 1 0) surface were investigated using density functional theory (DFT) calculations. The results showed that the adsorbates lie flat at the hollow site and form covalent bonds with surface Fe atoms. Large adsorption energies and charge transfers from Fe(1 1 0) to the adsorbates indicate chemisorptions.
APPLIED SURFACE SCIENCE
(2022)
Article
Energy & Fuels
Xuetao Shi, Qi Wang, Angela Violi
Summary: This study systematically investigates possible reaction pathways leading to the formation of five-membered rings, focusing on the formation of acenaphthene and acenaphthylene from different sites on naphthalene and phenanthrene. The relative importance of new reaction pathways is explored based on experimental data, providing a more complete description of cross-linking in soot models and the formation of embedded five-membered rings.
Article
Chemistry, Multidisciplinary
Qiyao Li, Junyi Gong, Ying Li, Ruoyao Zhang, Haoran Wang, Jianquan Zhang, He Yan, Jacky W. Y. Lam, Herman H. Y. Sung, Ian D. Williams, Ryan T. K. Kwok, Min-Hui Li, Jianguo Wang, Ben Zhong Tang
Summary: This study introduces a novel synthetic method to construct five-membered heterocyclic compounds with AIE characteristics under mild conditions, and achieves significant progress in cancer cell recognition and fluorescent patterning through a light-driven amplification strategy.
Article
Chemistry, Organic
Yan-Hua Fu, Kai Wang, Liguo Yang, Guang-Bin Shen, Xiao-Qing Zhu
Summary: This study investigated the mechanisms of the hydride transfer and hydrogen atom transfer reactions induced by electron transfer. The study also compared the hydrogen-donating abilities of different compounds.
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Applied
Jie Shen, Yu Xing, Lidong Fu, Yanze Li, Lei Cui, Zijun Zhou, Chunju Li, Jian Li
Summary: A cascade reaction of diynone and o-hydroxy aromatic aldimine under mild conditions has been developed. This protocol proceeds through sequential [3+2]/[4+4] cycloaddition and proton transfer processes, providing an efficient method for synthesizing a variety of dihydropyrrole fused eight-membered ring scaffolds.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
