Synthesis of Rationally Halogenated Buckybowls by Chemoselective Aromatic C−F Bond Activation

Abstract

Halogenated buckybowls or bowl-shaped polycyclic aromatic hydrocarbons (BS-PAHs) are key building blocks for the "bottom-up" synthesis of various carbon-based nanomaterials with outstanding potential in different fields of technology. The current state of the art provides quite a limited number of synthetic pathways to BS-PAHs; moreover, none of these approaches show high selectivity and tolerance of functional groups. Herein we demonstrate an effective route to BS-PAHs that includes directed intramolecular aryl-aryl coupling through C-F bond activation. The coupling conditions were found to be completely tolerant toward aromatic C-Br and C-Cl bonds, thus allowing the facile synthesis of rationally halogenated buckybowls with an unprecedented level of selectivity. This finding opens the way to functionalized BS-PAH systems that cannot be obtained by alternative methods.

The Mechanism of Cyclodehydrofluorination on γ‐Alumina

“…[14,15] Following this strategy, we were able to construct various polycyclic aromatic hydrocarbons (PAH) with near-quantitative yields. [14][15][16] Recently we have demonstrated that the C─F bond activation by aluminum oxide allows performing effective coupling in truly domino-like manner ( Figure 1). [17] The high efficiency and the possibility to perform the final transformation in solid state makes this approach highly attractive for the synthesis of virtually insoluble NGs.…”

Effect of the Cove Region Geometry in Polycyclic Aromatic Hydrocarbons on Alumina‐Assisted Cyclodehydrofluorination

“…This is mainly fueled by the demand from physicist chasing for the unique PAHs’ properties such as charge carrier mobilities, singlet fission, and many others . Naturally, family of PAHs consists of numerous subclasses, among which non‐planar PAHs bearing bowl‐shaped geometry exhibit highly interesting features, which cannot be properly investigated due to drastic lack of the synthetic approaches toward the so‐called buckybowls . The explanation for such a scarcity of methodologies in the seemingly well‐established field is mainly connected to the strain energies that originate from the valence angles’ deviations, resulting in non‐planar structures resembling a bowl.…”

Tailoring Diindenochrysene through Intramolecular Multi‐Assemblies by C−F Bond Activation on Aluminum Oxide

“…Althought he first two methods face both low group tolerance and moderate yields, the last one often possess highs electivity and frequentlyl eads to nearly quantitative yields showingt olerance to variousf unctional groups. [15,16] Diindeno [1,2,3,4-…”