The structural diversity of polycyclic aromatic hydrocarbons (PAHs) offers exciting opportunities for their applications. Yet, selective synthesis of such conjugated networks poses a formidable challenge. Compared to the prominence of transition-metal-catalyzed cross-coupling and oxidative Scholl reactions, cationic rearrangement in the synthesis of polycyclic aromatic hydrocarbon is an underexplored subject. In this study, we reveal that cationic intermediate generated from epoxy dibenzocycloheptanol can be transformed into acenes, azulene-embedded PAHs, and dibenzocycloheptanone derivatives. Reactive patterns, including Meinwald rearrangement, Nazarov cyclization, transannular aryl migration, and transannular Friedel-Crafts cyclization were identified. Both substrate structures and reaction temperature affect the reaction pathways in predictable and manageable manners. A mechanistic scheme was postulated as the working model to guide the reactivity for further application. Substrates containing heterocyclic and ferrocenyl groups exhibit similar reactivity profiles. The inquiry culminates in the selective synthesis of 5, 7, 12, 14-tetrasubstituted and pentacene derivatives. Our results demonstrate that polycyclic aromatic hydrocarbons can be selectively prepared with this cation-initiated strategy by methodically tuning the reactivity.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9244947 | PMC |
| http://dx.doi.org/10.1021/acsomega.2c01024 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Rapid access to functionalized nanographenes through a palladium-catalyzed multi-annulation sequence.
Chem Sci
January 2025
Institute of Chemistry, Academia Sinica 128 Academia Road, Section 2, Nankang Taipei 115201 Taiwan
Nanographenes and polycyclic aromatic hydrocarbons exhibit many intriguing physical properties and have potential applications across a range of scientific fields, including electronics, catalysis, and biomedicine. To accelerate the development of such applications, efficient and reliable methods for accessing functionalized analogs are required. Herein, we report the efficient synthesis of functionalized small nanographenes from readily available iodobiaryl and diarylacetylene derivatives a one-pot, multi-annulation sequence catalyzed by a single palladium catalyst.
View Article and Find Full Text PDF[Research advance of solid-phase microextraction based on covalent organic framework materials].
Se Pu
February 2025
School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
Solid-phase microextraction (SPME) is a fast and simple sample preparation technique that enables the enrichment of analytes, and it is used in combination with other detection techniques to provide accurate and sensitive analytical methods. SPME is widely used in environmental monitoring, food safety, life analysis, biomedicine, and other applications. The extractive coating is the core of the SPME technique, and the properties of the extractive coating greatly influence extraction selectivity and efficiency, as well as the enrichment effect.
View Article and Find Full Text PDFAtmospheric pah concentrations in a semi-urban site: temporal variation, risk assessment, source identification and estimation of levels in diverse environments.
Environ Toxicol Chem
January 2025
Department of Environmental Engineering, Faculty of Engineering, Bursa Uludag University, 16059 Nilüfer/Bursa-Türkiye.
This study evaluates atmospheric polycyclic aromatic hydrocarbon (PAH) concentrations in a semi-urban area, Görükle, Turkey, from June 2021 to February 2022. The average concentration of ∑16 PAHs was 24.85 ± 19.
View Article and Find Full Text PDFChemical Dissipation from Outdoor Plastics: The Significant Impact of Transformation Processes Revealed by Adjusted Mass Transfer Modeling.
Environ Sci Technol
January 2025
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
Chemicals in plastics raise significant concerns for potential adverse environmental and health impacts. However, dissipation kinetics and fluxes of chemicals from outdoor plastic products remain largely uncharacterized, hindering the accurate assessment of their environmental exposure. This study quantified outdoor dissipation profiles for 20 "priority" chemicals, including sunscreens (benzophenone, benzophenone-3, octyl salicylate, etc.
View Article and Find Full Text PDFTyre rubber exposure causes oxidative stress and intracellular damage in the Baltic clam (Macoma balthica).
Environ Sci Pollut Res Int
January 2025
Marine and Freshwater Solutions, Finnish Environment Institute, Latokartanonkaari 11, 00790, Helsinki, Finland.
Car tyres are considered to release a substantial amount of particles to the environment. Due to the high emission volumes and the chemical risks associated with tyre rubber, there is an urgent need to quantify their ecotoxicological effects. The effects of exposure to particles derived from end-of-life tyres were investigated on the Baltic clam (Macoma balthica), which is one of the key invertebrate species living in the soft-bottom sediments of the northern Baltic Sea.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!