The Effect of Benzannulation on the Structures, Reactivity and Molecular Dynamics of Indenes, Pentalenes, Azulenes and Related Molecules

Michael J McGlinchey

doi:10.3390/molecules27123882

The Effect of Benzannulation on the Structures, Reactivity and Molecular Dynamics of Indenes, Pentalenes, Azulenes and Related Molecules

Molecules. 2022 Jun 17;27(12):3882. doi: 10.3390/molecules27123882.

Author

Michael J McGlinchey¹

Affiliation

¹ School of Chemistry, University College Dublin, Belfield, D04 V1W8 Dublin 4, Ireland.

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, 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.

Keywords: X-ray crystallography; benzazulenes; benzyne cycloadditions; dibenzpentalenes; isoindenes; organometallic molecular brake; sigmatropic and haptotropic migrations; tetracenes.

Publication types

Review

MeSH terms

Azulenes* / chemistry
Crystallography, X-Ray
Indenes* / chemistry
Molecular Dynamics Simulation

Substances

Azulenes
Indenes

Grants and funding

This research was funded for many years by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Petroleum Research Fund (PRF), administered by the American Chemical Society, and by Science Foundation Ireland (SFI).