Benzannulated Cycloheptanones from Binaphthyl Platforms

Grégory Pieters (1) , Kamal Sbargoud (1) , Alexandre Bridoux (1) , Anne Gaucher (1) , Sylvain Marque (1) , Fabien Bourdreux (1) , Jérôme Marrot (1) , David Flot (2) , Guillaume Wantz (3) , Olivier Dautel (4) , Damien Prim (1)

1 ILV - Institut Lavoisier de Versailles
2 EMBL Grenoble - Laboratoire européen de biologie moléculaire - European Molecular Biology Laboratory
3 IMS - Laboratoire de l'intégration, du matériau au système
4 ICGM ICMMM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier

Preparations of benzannulated cycloheptanones starting from unique binaphthyl molecular platforms are described. Binaphthyl acetic acids proved suitable percursors for fused cycloheptanone architectures. Seven-membered rings embedded in binaphthyl units were selectively generated by use of Eaton's reagent. Isomeric helical architectures arising from electrophilic cyclisation processes at second reaction sites in the precursors could also be obtained under different acidic conditions. Unambiguous discrimination between isomeric geometries was provided by multiple quantum NMR sequences. DFT calculations were performed and gave evidence of different behaviour of the substrates towards intramolecular electrophilic substitution. The theoretical approach confirmed the experimental results, agreeing completely with X-ray data.

Mots clés: Helical structures; Density functional calculations; NMR spectroscopy; Multiple quantum NMR

Domaines: Chimie organique

Grégory Pieters, Kamal Sbargoud, Alexandre Bridoux, Anne Gaucher, Sylvain Marque, et al.. Benzannulated Cycloheptanones from Binaphthyl Platforms. European Journal of Organic Chemistry, 2012, 2013 (3), pp.490-497. ⟨10.1002/ejoc.201201370⟩. ⟨hal-00797777⟩