Configurationally stable dithia[7]helicene and dithia-quasi[8]circulene fused dithiolones - Université d'Angers Accéder directement au contenu
Article Dans Une Revue Organic Chemistry Frontiers Année : 2022

Configurationally stable dithia[7]helicene and dithia-quasi[8]circulene fused dithiolones

Maxime Baudillon
Thomas Cauchy
Nicolas Vanthuyne
Narcis Avarvari
Flavia Pop


Dithia-[7]helicene and quasi[8]circulene have been formed on the 1,3-dithiol-2-one ring by oxidative dehydrocyclisation of bis-naphthothiophenyl-1,3-dithiol-2-one. Quasi-circulenes are easily obtained at room temperature by successive dehydrocyclisations regardless the amount of oxidation reagent whereas selectivity towards helicene, involving a single dehydrocyclisation, has been achieved only at low temperature. DFT calculations suggest a mechanism via a dication intermediate rather than a mono-cation for the formation of the quasicirculenes whereas the helicene should be formed via a radical cation intermediate. While dithia[7]helicene is known to give stable stereoisomers, here the unsubstituted dithiaquasi[8]circulene shows unprecedented configurational stability of the enantiomers, with a theoretically estimated enantiomerisation energy barrier of 30.4 kcal/mol, in excellent agreement with the experimentally determined value of 29.8 kcal/mol. The enantiomers of both helicene and quasi-circulene have been separated by chiral chromatography and their absolute configuration assigned from the calculated CD spectra.


Chimie organique
Fichier principal
Vignette du fichier
Pop_Avarvari_09_06_22_revised.pdf (1.56 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03855078 , version 1 (16-11-2022)



Maxime Baudillon, Thomas Cauchy, Nicolas Vanthuyne, Narcis Avarvari, Flavia Pop. Configurationally stable dithia[7]helicene and dithia-quasi[8]circulene fused dithiolones. Organic Chemistry Frontiers, 2022, 9 (16), pp.4260-4270. ⟨10.1039/D2QO00921H⟩. ⟨hal-03855078⟩
10 Consultations
52 Téléchargements



Gmail Facebook X LinkedIn More