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Updated: Oct 20, 2025

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyltroponeiron
Published on: August 12, 2019
Synthesis and Characterization of 1-Hydroxy-4,5-arene-Fused Tropylium Derivatives
Takuya Kodama1,2, Yuki Kawashima1, Kenta Uchida1
1Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
Abstract:
The properties of 1-hydroxy-4,5-arene-fused tropyliums were assessed based on experimental and theoretical investigations. An X-ray crystallographic analysis revealed a decrease of bond alternation in the seven-membered ring of 1-hydroxy-4,5-benzotropylium derivatives compared with that of the parent 4,5-benzotropones, which is indicative of an increase in aromaticity upon protonation. NICS and AICD calculations also supported the increased aromaticity of 1-hydroxy-4,5-arene-fused tropylium. The pKa values for a series of 1-hydroxy-4,5-arene-fused tropylium derivatives were also determined.
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