I. Doğan

Elucidating the Structural Isomerism of Fluorescent Strigolactone Analogue CISA-1

H. Goossens, T.S.A Heugebaert, B. Dereli, M. Van Overtveldt, O. Karahan, I. Doğan, M. Waroquier, V. Van Speybroeck, V. Aviyente, S. Catak, C.V. Stevens
European Journal of Organic Chemistry
2015 (6), 1211–1217


The synthesis of a new potent strigolactone analogue (CISA-1), resulting in the formation of two interconverting structural isomers, which could not be identified, was recently reported by Rasmussen et al [Molecular Plant, 2013, 6, 100]. In the present study, a combined computational and experimental approach is used to identify the exact nature of these structural isomers. While standard experimental techniques were not able to determine the identity of the isomers, chromatographic methods excluded E/Z isomerisation. Computational 1H NMR chemical shift values and DFT calculations on interconversion barriers strongly suggest that the CISA-1 isomers were interconverting (Z)-configured atropisomers.

Solvent-Catalyzed Ring-Chain-Ring Tautomerization in Axially Chiral Compounds

A. Yıldırım, A. Konuklar, S. Catak, V. Van Speybroeck, M. Waroquier, I. Doğan, V. Aviyente
Chemistry - A European Journal
18 (40), 12725-12732


The mechanism of ring–chain–ring tautomerization and the prominent effect of the solvent environment have been computationally investigated in an effort to explain the enantiomeric interconversion observed in 2-oxazolidinone derivatives, heterocyclic analogues of biphenyl atropisomers, which were isolated as single stable enantiomers and have the potential to be used as axially chiral catalysts. This study has shed light on the identity of the intermediate species involved in the ring–chain–ring tautomerization process as well as the catalytic effect of polar protic solvents. These mechanistic details will prove very useful in predicting and understanding ring–chain tautomeric equilibria in similar heterocyclic systems and will further enable experimentalists to devise appropriate experimental conditions in which axially chiral catalysts remain stable as single enantiomers.

Modeling Ring-chain-ring Tautomerization of N-(o-aryl)-4-Hydroxy-2-oxazolidinone Derivatives

Abstract PII 141

Conference / event / venue 

Ninth Triennial Congress of the World Association of Theoretical and Computational Chemists (WATOC)
Santiago de Compostela, Spain
Sunday, 17 July, 2011 to Friday, 22 July, 2011
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