Synthesis of Azepine- or Azocine-Embedded Hexabenzocoronene-Based Nanographenes

Synlett ◽  
2021 ◽  
Author(s):  
Bin Ma ◽  
Ming-Jun Xiao ◽  
Pi-Jin Liu ◽  
Peng An
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Membered Ring ◽  
Synthetic Methods ◽  
Synthetic Method ◽  
Synthetic Route ◽  
Heteroatom Doping ◽  
Large Group ◽  
Planar Structures ◽  
Polycyclic Aromatic

Classical polycyclic aromatic hydrocarbons (PAHs) are a large group of π-conjugated planar structures. To explore more properties of PAHs, new structures were designed including nonplanar topologies and heteroatom-doping moieties. As an important nanographene (NG) unit, hexabenzocoronene (HBC) and its derivatives have been intensively researched. Numbers of HBC-based nonplanar NGs were developed and the heteroatom-doped HBC-based NGs have been designed and synthesized as well. Herein, we synthetically summarized some synthetic methods for seven- or eight-membered ring containing HBC-based NGs, and discussed our newly synthesized azepine- or azocine-embedded NGs by using a modified synthetic route and a traditional Müllen’s synthetic method, respectively.

scholarly journals How to add a five-membered ring to polycyclic aromatic hydrocarbons (PAHs) – molecular mass growth of the 2-naphthyl radical (C10H7) to benzindenes (C13H10) as a case study

2019 ◽  
Vol 21 (30) ◽  
pp. 16737-16750 ◽  
Author(s):  
Long Zhao ◽  
Matthew Prendergast ◽  
Ralf I. Kaiser ◽  
Bo Xu ◽  
Utuq Ablikim ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Molecular Mass ◽  
Aromatic Hydrocarbons ◽  
Membered Ring ◽  
Growth Processes ◽  
Mass Growth ◽  
Aryl Radicals ◽  
Polycyclic Aromatic

The reaction of aryl radicals with allene/methylacetylene leads to five-membered ring addition in PAH growth processes.

scholarly journals Site-Selective [2+2+n] Cycloadditions for Rapid, Scalable Access to Alkynylated Polycyclic Aromatic Hydrocarbons

2019 ◽  
Author(s):  
Gavin R. Kiel ◽  
Harrison Bergman ◽  
T. Don Tilley
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Structural Complexity ◽  
Building Blocks ◽  
Synthetic Methods ◽  
Proof Of Concept ◽  
Site Selectivity ◽  
Polycyclic Aromatic ◽  
Site Selective ◽  
Nanometer Regime

Polycyclic aromatic hydrocarbons (PAHs) are attractive synthetic building blocks for more complex conjugated nanocarbons, but their use for this purpose requires appreciable quantities of a PAH with reactive functional groups. Despite tremendous recent advances, most synthetic methods cannot satisfy these demands. Here we present a general and scalable [2+2+n] (n = 1 or 2) cycloaddition strategy to access PAHs that are decorated with synthetically versatile alkynyl groups and its application to seven structurally diverse PAH ring systems (thirteen new alkynylated PAHs in total). The critical discovery is the site-selectivity of an Ir-catalyzed [2+2+2] cycloaddition, which preferentially cyclizes tethered diyne units with preservation of other (peripheral) alkynyl groups. The potential for generalization of the site-selectivity to other [2+2+n] reactions is demonstrated by identification of a Cp<sub>2</sub>Zr-mediated [2+2+1] / metallacycle transfer sequence for synthesis of an alkynylated, selenophene-annulated PAH. The new PAHs are excellent synthons for macrocyclic conjugated nanocarbons. As a proof of concept, four were subjected to Mo catalysis to afford large, PAH-containing arylene ethylene macrocycles, which possess a range of cavity sizes reaching well into the nanometer regime. More generally, this work is a demonstration of how site-selective reactions can be harnessed to rapidly build up structural complexity in a practical, scalable fashion.

scholarly journals Diversity-oriented synthesis of nanographenes enabled by dearomative annulative π-extension

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wataru Matsuoka ◽  
Hideto Ito ◽  
David Sarlah ◽  
Kenichiro Itami
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Template Synthesis ◽  
Science And Technology ◽  
Synthetic Methods ◽  
Structure Property ◽  
Oriented Growth ◽  
Diversity Oriented Synthesis ◽  
Potential Applications ◽  
Polycyclic Aromatic

AbstractNanographenes and polycyclic aromatic hydrocarbons (PAHs) are among the most important classes of compounds, with potential applications in nearly all areas of science and technology. While the theoretically possible number of nanographene structures is extraordinary, most of these molecules remain synthetically out of reach due to a lack of programmable and diversity-oriented synthetic methods, and their potentially huge structure-property diversity has not been fully exploited. Herein we report a diversity-oriented, growth-from-template synthesis of nanographenes enabled by iterative annulative π-extension (APEX) reactions from small PAH starting materials. The developed dearomative annulative π-extension (DAPEX) reaction enables π-elongation at the less-reactive M-regions of PAHs, and is successfully combined with complementary APEX reactions that occur at K- and bay-regions to access a variety of previously untapped nanographenes.

scholarly journals LEVELS OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) IN FISH SAMPLES FROM DIFFERENT PROCESSING METHODS

2020 ◽  
Vol 45 (6) ◽  
Author(s):  
A.U. Itodo ◽  
V.O. Nnodim ◽  
S. Ande ◽  
H.U. Itodo ◽  
O. Ofoegbu
Keyword(s):  
Water Pollution ◽  
Gas Chromatography ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Membered Ring ◽  
Diagnostic Ratios ◽  
Smoked Fish ◽  
Fish Samples ◽  
Polycyclic Aromatic ◽  
Petrogenic Source

Fish is easily contaminated from water prone to water pollution. In this study, the levels of polycyclic aromatic hydrocarbons (PAHs) in fish samples processed, using three methods and marketed in Makurdi, Benue state, were determined. The samples were coded as SF (Smoked Fish), SD (Sundried) and FD (fried) fish samples. PAHs in the samples were quantified, using gas chromatography – mass spectrometer (GC-MS). The Ʃ16PAH concentrations were in the range of 0.2- 10.0 mg/kg. Both LPAHs/HPAHs and the binary diagnostic ratios of PAHs indicated pyrogenic and petrogenic sources Ʃ16PAH and their dominant PAH ring-types were separately computed for each sample. The six-membered ring PAHs in smoked fish was 32.07% (with Bezo(ghi)perylene as most dominant). High levels of six member ring PAHs (Dibenz(a,h) anthracene) were also found in Sundried fish and fried fish contain Dibenz(a,h) anthracene. Generally, the PAHs concentrations in the samples, pointed more at pyrogenic than the petrogenic source. With exception of the five and six membered rings, estimated PAH levels were within the NAFDAC permissible limits.

scholarly journals Site-Selective [2+2+n] Cycloadditions for Rapid, Scalable Access to Alkynylated Polycyclic Aromatic Hydrocarbons

2019 ◽  
Author(s):  
Gavin R. Kiel ◽  
Harrison Bergman ◽  
T. Don Tilley
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Structural Complexity ◽  
Building Blocks ◽  
Synthetic Methods ◽  
Proof Of Concept ◽  
Site Selectivity ◽  
Polycyclic Aromatic ◽  
Site Selective ◽  
Nanometer Regime

Polycyclic aromatic hydrocarbons (PAHs) are attractive synthetic building blocks for more complex conjugated nanocarbons, but their use for this purpose requires appreciable quantities of a PAH with reactive functional groups. Despite tremendous recent advances, most synthetic methods cannot satisfy these demands. Here we present a general and scalable [2+2+n] (n = 1 or 2) cycloaddition strategy to access PAHs that are decorated with synthetically versatile alkynyl groups and its application to seven structurally diverse PAH ring systems (thirteen new alkynylated PAHs in total). The critical discovery is the site-selectivity of an Ir-catalyzed [2+2+2] cycloaddition, which preferentially cyclizes tethered diyne units with preservation of other (peripheral) alkynyl groups. The potential for generalization of the site-selectivity to other [2+2+n] reactions is demonstrated by identification of a Cp<sub>2</sub>Zr-mediated [2+2+1] / metallacycle transfer sequence for synthesis of an alkynylated, selenophene-annulated PAH. The new PAHs are excellent synthons for macrocyclic conjugated nanocarbons. As a proof of concept, four were subjected to Mo catalysis to afford large, PAH-containing arylene ethylene macrocycles, which possess a range of cavity sizes reaching well into the nanometer regime. More generally, this work is a demonstration of how site-selective reactions can be harnessed to rapidly build up structural complexity in a practical, scalable fashion.

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