Highly Substituted Acephenanthrylenes and Their π-Extended Derivatives: Syntheses, Structural Analyses, and Properties

Abstract

This investigation demonstrates that a series of (highly) substituted acephenanthrylenes (APs) 2, benzo[l]acephenanthrylene 3, and dicyclopenta[cd,mn]pyrene 4 are easily prepared by palladium-catalyzed cycloaromatization of 2,3-diethynylbiphenyls 1. The first nonpyrolysis synthesis of 4 by two-fold cycloaromatization was achieved in a high yield. This synthetic protocol has two crucial advantages: facile introduction of various substituents and efficient extension of the AP backbone.

Constructing 1-Ethoxyphenanthro[9,10-e]acephenanthrylene for the Synthesis of a Polyaromatic Hydrocarbon Containing a Formal Azulene Unit

“…PAP is a phenanthrene-fused acephenanthrylene (AP), which is a cyclopentannulated-PAH (CP-PAH), and parent AP was known since 1985 . Despite various synthetic approaches for substituted AP motifs, − herein, we adopted an oxidative aromatic coupling route to synthesize 1-ethoxy­[9,10- e ]­PAP 8 in order to use it to construct diphenanthro-benzo­[ f ]­azulene 9 with [30]­π-electrons in the periphery, which may be viewed as a tribenzo-fused 5-NA . The ground-state electronic properties of 9 were studied by both experimental and computational approaches.…”

Fused diethynylbenzenes and phenanthrenes via arynes with alkynylsilanes

“…Of note, due to the extremely strong deshielding effect, the chemical shift of the substituent H1 atom at the C1 position in the 1 H NMR spectrum is around 10.48 ppm. 16 We determined the structures of 8g by X-ray single crystal diffraction. 14 In a dry environment protected by argon gas, 8e was used as the reference, and D 2 O and CD 3 CN were used respectively for isotope labeling experiments.…”

“…Of note, due to the extremely strong deshielding effect, the chemical shift of the substituent H1 atom at the C1 position in the 1 H NMR spectrum is around 10.48 ppm. 16 We determined the structures of 8g by X-ray single crystal diffraction. 14…”