Heterohelicenes through 1,3-dipolar cycloaddition of sydnones with arynes: synthesis, origins of selectivity, and application to pH-triggered chiroptical switch with CPL sign reversal - Archive ouverte HAL Access content directly
Journal Articles JACS Au Year : 2021

Heterohelicenes through 1,3-dipolar cycloaddition of sydnones with arynes: synthesis, origins of selectivity, and application to pH-triggered chiroptical switch with CPL sign reversal

(1) , (2) , (1) , (3) , (1) , (1) , (2) , (1)
1
2
3

Abstract

Regioselective access to heterohelicenes through the 1,3-dipolar cycloaddition of sydnones with arynes is described. Novel access to sydnones and poly(hetero)aromatic aryne precursors allowed the introduction of chemical diversity over multiple positions of the helical scaffolds. The origins of the unconventional regioselectivity during the cycloaddition steps was systematically investigated using density functional theory (DFT) calculations, unveiling the key features that control this reactivity, namely, face-to-face ($\pi \cdot \cdot \cdot \pi$) or edge-to-face (C−H$\cdot \cdot \cdot \pi$) interactions, primary orbital interactions and distortion from coplanarity in the transition structures (TSs) of the transformation. From the library of 24 derivatives synthesized, a pyridyl containing derivative displayed reversible, red-shifted, pH-triggered chiroptical switching properties, with CPL-sign reversal. It is found that protonation of the helicene causes a change of the angle between the electric and magnetic dipole moments related to the S$_1$ → S$_0$ transition, resulting in this rare case of reversible CPL sign inversion upon application of an external stimulus.
Fichier principal
Vignette du fichier
jacsau.1c00084.pdf (6.26 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

cea-03228272 , version 1 (18-05-2021)

Licence

Attribution - NonCommercial - NoDerivatives - CC BY 4.0

Identifiers

Cite

Expédite Yen-Pon, Floris Buttard, Lucas Frédéric, Pierre Thuéry, Frédéric Taran, et al.. Heterohelicenes through 1,3-dipolar cycloaddition of sydnones with arynes: synthesis, origins of selectivity, and application to pH-triggered chiroptical switch with CPL sign reversal. JACS Au, In press, 1 (6), pp.807-818. ⟨10.1021/jacsau.1c00084⟩. ⟨cea-03228272⟩
38 View
86 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More