Open AccessExploring the Acid-Catalyzed Reactions of 10,11-Epoxy-Dibenzo[a,d]cycloheptan-5-ol as the Synthetic Modules toward Polycyclic Aromatic Scaffolds
Author(s) -
ChingChi Hsu,
Cian-Jhe Zheng,
YingYann Wu,
Wen-Hsuan Fan,
ChihHsiu Lin
Publication year - 2022
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.2c01024
Subject(s) - reactivity (psychology) , chemistry , cationic polymerization , azulene , polycyclic aromatic hydrocarbon , aryl , catalysis , substrate (aquarium) , combinatorial chemistry , organic chemistry , alkyl , medicine , alternative medicine , oceanography , pathology , geology
The structural diversity of polycyclic aromatic hydrocarbons (PAHs) offers exciting opportunities for their applications. Yet, selective synthesis of such conjugated networks poses a formidable challenge. Compared to the prominence of transition-metal-catalyzed cross-coupling and oxidative Scholl reactions, cationic rearrangement in the synthesis of polycyclic aromatic hydrocarbon is an underexplored subject. In this study, we reveal that cationic intermediate generated from epoxy dibenzocycloheptanol can be transformed into acenes, azulene-embedded PAHs, and dibenzocycloheptanone derivatives. Reactive patterns, including Meinwald rearrangement, Nazarov cyclization, transannular aryl migration, and transannular Friedel-Crafts cyclization were identified. Both substrate structures and reaction temperature affect the reaction pathways in predictable and manageable manners. A mechanistic scheme was postulated as the working model to guide the reactivity for further application. Substrates containing heterocyclic and ferrocenyl groups exhibit similar reactivity profiles. The inquiry culminates in the selective synthesis of 5, 7, 12, 14-tetrasubstituted C 2 h and C 2 v pentacene derivatives. Our results demonstrate that polycyclic aromatic hydrocarbons can be selectively prepared with this cation-initiated strategy by methodically tuning the reactivity.