molecules-logo

Journal Browser

Journal Browser

Benzannulations in Organic Synthesis

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Organic Chemistry".

Deadline for manuscript submissions: closed (31 December 2022) | Viewed by 6623

Special Issue Editor


E-Mail Website
Guest Editor
C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26505, USA
Interests: organic synthesis; methodology; medicinal chemistry; microwave chemistry

Special Issue Information

Dear Colleagues,

This Special Issue of Molecules comprises contributions addressing the methodology and synthesis of highly substituted benzenes and other aromatic ring systems. The synthesis of substituted aromatic rings is a longstanding challenge in organic chemistry. The aromatic substitution of pre-existing arenes is the most common—and generally most reliable—approach, but the inherent limitations, inefficiencies, and complexities of this approach amplify with increasing substitution. Convergent benzannulation processes create opportunities for preferred solutions for highly substituted benzene rings. Polycyclic and heterocyclic aromatic rings present analogous challenges and opportunities. Research in this area advances the field of organic synthesis and accelerates research in related fields like medicinal chemistry, energy, and materials, which rely on small-molecule synthesis to drive innovation. Recent innovations in benzannulation methodology are highlighted in this Special Issue.

Dr. Gregory B. Dudley
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • benzannulation
  • cycloaddition
  • cycloisomerization
  • cyclotrimerization
  • two-component coupling
  • three-component coupling
  • target-oriented synthesis
  • convergent synthesis
  • organic synthesis
  • benzenoids
  • aromatic rings
  • heterocyclic chemistry
  • polycyclic aromatic hydrocarbons

Published Papers (4 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

14 pages, 1143 KiB  
Article
A Novel Method to Construct 2-Aminobenzofurans via [4 + 1] Cycloaddition Reaction of In Situ Generated Ortho-Quinone Methides with Isocyanides
by Huaxin Lin, Senling Tang, Yang Pan, Peng Liang, Xiaofeng Ma, Wei Jiao and Huawu Shao
Molecules 2022, 27(23), 8538; https://doi.org/10.3390/molecules27238538 - 04 Dec 2022
Cited by 1 | Viewed by 1367
Abstract
A new approach for the synthesis of 2-aminobenzofurans has been described via Sc(OTf)3 mediated formal cycloaddition of isocyanides with the in situ generated ortho-quinone methides (o-QMs) from o-hydroxybenzhydryl alcohol. Notably, as a class of readily available and highly [...] Read more.
A new approach for the synthesis of 2-aminobenzofurans has been described via Sc(OTf)3 mediated formal cycloaddition of isocyanides with the in situ generated ortho-quinone methides (o-QMs) from o-hydroxybenzhydryl alcohol. Notably, as a class of readily available and highly active intermediates, o-QMs were first used in the construction of benzofurans. This [4 + 1] cycloaddition reaction provides a straightforward and efficient methodology for the construction of 2-aminobenzofurans scaffold in good yield (up to 93% yield) under mild conditions. Full article
(This article belongs to the Special Issue Benzannulations in Organic Synthesis)
Show Figures

Scheme 1

19 pages, 2302 KiB  
Article
Lewis Acid-Catalyzed 2,3-Dihydrofuran Acetal Ring-Opening Benzannulations toward Functionalized 1-Hydroxycarbazoles
by Shaoren Yuan, Gabriel Guerra Faura, Hailey E. Areheart, Natalie E. Peulen and Stefan France
Molecules 2022, 27(23), 8344; https://doi.org/10.3390/molecules27238344 - 30 Nov 2022
Cited by 3 | Viewed by 1994
Abstract
The development of a Lewis acid-catalyzed, intramolecular ring-opening benzannulation of 5-(indolyl)2,3-dihydrofuran acetals is described. The resulting 1-hydroxycarbazole-2-carboxylates are formed in up to 90% yield in 1 h. The dihydrofuran acetals are readily accessed from the reactions of enol ethers and α-diazo-β-indolyl-β-ketoesters. To highlight [...] Read more.
The development of a Lewis acid-catalyzed, intramolecular ring-opening benzannulation of 5-(indolyl)2,3-dihydrofuran acetals is described. The resulting 1-hydroxycarbazole-2-carboxylates are formed in up to 90% yield in 1 h. The dihydrofuran acetals are readily accessed from the reactions of enol ethers and α-diazo-β-indolyl-β-ketoesters. To highlight the method’s synthetic utility, a formal total synthesis of murrayafoline A, a bioactive carbazole-containing natural product, was undertaken. Full article
(This article belongs to the Special Issue Benzannulations in Organic Synthesis)
Show Figures

Figure 1

9 pages, 3072 KiB  
Article
Supramolecular Design Strategy of a Water-Soluble Diphenylguanidine-Cyclodextrin Polymer Inclusion Complex
by Junqiang Guo, Liwei Lin, Yuping Wang, Wang Zhang, Guowang Diao and Yuanzhe Piao
Molecules 2022, 27(20), 6919; https://doi.org/10.3390/molecules27206919 - 15 Oct 2022
Cited by 2 | Viewed by 1283
Abstract
Diphenylguanidine (DPG) is a widely used secondary accelerator for the vulcanization of natural rubber (NR) latex. However, its low water solubility and high toxicity limit its use in high-end NR products. In this study, a water-soluble inclusion complex of DPG and a β [...] Read more.
Diphenylguanidine (DPG) is a widely used secondary accelerator for the vulcanization of natural rubber (NR) latex. However, its low water solubility and high toxicity limit its use in high-end NR products. In this study, a water-soluble inclusion complex of DPG and a β-cyclodextrin polymer (β-CDP), termed DPG-β-CDP, was prepared through supramolecular interactions and characterized using Fourier-transform infrared spectroscopy, 1H NMR, scanning electron microscopy, and UV-vis spectroscopy techniques. In comparison with that of DPG, the water solubility of DPG-β-CDP was greatly enhanced because of the water-soluble host molecule. The molar ratio of DPG to the CD unit in β-CDP was determined to be 1:1. At 25 °C, the binding constant of DPG-β-CDP was found to be 9.2 × 105 L/mol by UV-vis spectroscopy. The proposed method for forming inclusion complexes with high potential for use as water-soluble vulcanization accelerators is promising. Full article
(This article belongs to the Special Issue Benzannulations in Organic Synthesis)
Show Figures

Figure 1

Review

Jump to: Research

27 pages, 14624 KiB  
Review
The Effect of Benzannulation on the Structures, Reactivity and Molecular Dynamics of Indenes, Pentalenes, Azulenes and Related Molecules
by Michael J. McGlinchey
Molecules 2022, 27(12), 3882; https://doi.org/10.3390/molecules27123882 - 17 Jun 2022
Cited by 1 | Viewed by 1268
Abstract
The stabilising effect of benzannulation on isoindenes formed in the course of sigmatropic shifts of (C5H5)Fe(CO)2 or of organo-silyl groups, and on exocyclic allyl intermediates in the course of haptotropic shifts of organometallic fragments over polycyclic skeletons (fluorene, [...] Read more.
The stabilising effect of benzannulation on isoindenes formed in the course of sigmatropic shifts of (C5H5)Fe(CO)2 or of organo-silyl groups, and on exocyclic allyl intermediates in the course of haptotropic shifts of organometallic fragments over polycyclic skeletons (fluorene, cyclopenta[def]phenanthrene, syn and anti dibenzpentalenes) is exemplified. This approach led to the development of the first organometallic molecular brake. Benzyne cycloadditions to anthracenes to form triptycenes also led to unexpected or multiple adducts that were characterised by X-ray crystallography. Synthetic routes to the previously elusive benz[cd]azulene system are presented. Finally, the complete mechanism of the stepwise assembly of dispiro- and diindenyltetracenes from fluorenylallenes is presented, whereby every intermediate has been unambiguously structurally characterised. Full article
(This article belongs to the Special Issue Benzannulations in Organic Synthesis)
Show Figures

Figure 1

Back to TopTop