Unexpected Michael Additions on the Way to 2.3,8.9‐Dibenzanthanthrenes with Interesting Structural Properties

Abstract

The synthesis and properties of a new polycyclic aromatic hydrocarbon containing eight annulated rings and based on the anthanthrene core is described. An unexpected, nucleophile-dependent Michael addition to a dibenzanthanthrene-1,7-dione is found, giving a product with three triisopropylsilylacetylene units and a remarkable solid-state structure (as determined by X-ray crystallography).

Stable 2D Bisthienoacenes: Synthesis, Crystal Packing, and Photophysical Properties

“…Four TIPS substituents are located at the 1, 6, 7, and 12 positions of the bisthienotetracene and bisthienopentacene skeletons (Figure a,b). Because of the steric hindrance between the neighboring TIPS groups, the 2D skeletons are not fully planar but slightly twisted, which is similar to the previously reported bistetracenes (Figure S1 in the Supporting Information) –. The 2D aromatic scaffold of longer conjugated BTP‐4ITPS is more contorted than that of BTT‐4TIPS.…”

“…Through thiophene annulation and extension of conjugation, these novel bisthienoacenes exhibit rather high stability under ambient conditions but maintain narrow HOMO–LUMO gaps. To our surprise, different from previous reported bistetracenes, only four‐fold TIPS‐substituted products were isolated, indicating both 1,2‐ and 1,4‐addition occurred at the α,β‐unsaturated ketone moieties (highlighted in dashed ovals, Scheme ) . The electrochemical and optical properties, crystal packing, and charge carrier transport properties were investigated in detail.…”

Low Bandgap Bistetracene‐Based Organic Semiconductors Exhibiting Air Stability, High Aromaticity and Mobility

“…This enlargement was not very clear, as it has been disclosed that the intramolecular Friedel–Crafts reaction of the methyl 2‐(pyren‐1‐yl)benzoate with methanesulfonic acid led to the formation exclusively of the 5‐membered ring product . Recently, Tykwinski et al showed that the intramolecular Friedel–Crafts reaction with dimethyl 2,2′‐(3,8‐diethylpyrene‐1,6‐diyl)dibenzoic acid using polyphosphoric acid upon heating gave a bistetracene–dione ( BT ‐dione) in 85 % yield . They found that the synthesised BT ‐dione has a special reactivity with lithium TIPS–acetylene in which competition between 1,2‐ and 1,4‐addition occurs and leads to very low yield of the bistetracene skeleton …”

Reductive Aromatization/Dearomatization and Elimination Reactions to Access Conjugated Polycyclic Hydrocarbons, Heteroacenes, and Cumulenes

“…Two‐dimensional CPMs have been formed using reductive aromatization with Sn II /HCl, for example, pentalenoacene dimers, bistetracenes, benzannulated perylenes, anthanthrenes, dibenzanthanthrenes (e.g., 2.3,8.9‐dibenzanthanthrene 32 , Figure ), and other larger graphene fragments . Morin and co‐workers demonstrated promising performance in OFETs and organic solar cells for anthanthrene derivatives, suggesting that the study of these larger CPMs holds promise …”