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Updated: Sep 21, 2025

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyltroponeiron
Published on: August 12, 2019
Nickel-catalyzed skeletal transformation of tropone derivatives via C-C bond activation: catalyst-controlled access
Takuya Kodama1,2, Kanako Saito1, Mamoru Tobisu1,2
1Department of Applied Chemistry, Graduate School of Engineering, Osaka University Suita Osaka 565-0871 Japan tobisu@chem.eng.osaka-u.ac.jp.
Abstract:
We report herein on nickel-catalyzed carbon-carbon bond cleavage reactions of 2,4,6-cycloheptatrien-1-one (tropone) derivatives. When a Ni/N-heterocyclic carbene catalyst is used, decarbonylation proceeds with the formation of a benzene ring, while the use of bidentate ligands in conjunction with an alcohol additive results in a two-carbon ring contraction with the generation of cyclopentadiene derivatives. The latter reaction involves a nickel-ketene complex as an intermediate, which was characterized by X-ray crystallography. The choice of an appropriate ligand allows for selective synthesis of four different products via the cleavage of a seven-membered carbocyclic skeleton. Reaction mechanisms and ligand-controlled selectivity for both types of ring contraction reactions were also investigated computationally.
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