Expanded [2,1][n]Carbohelicenes with 15- and 17-Benzene Rings.
J Am Chem Soc
; 145(21): 11553-11565, 2023 May 31.
Article
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| MEDLINE
| ID: mdl-37202849
ABSTRACT
Expanded carbohelicenes with structures fused to 15- and 17-benzene were successfully synthesized. Establishing a new synthetic strategy is crucial to realize the development of longer expanded [2,1][n]helicenes with a kekulene-like projection drawing structure. This article describes the sequential integration of the π-elongating Wittig reaction of functionalized phenanthrene units and ring-fusing Yamamoto coupling for the synthesis of [2,1][15]helicenes and [2,1][17]helicenes. X-ray crystallographic structures, photophysical properties, and density functional theory (DFT) calculations revealed the unique characteristics of the synthesized expanded helicenes. Furthermore, because of the high enantiomerization barrier derived from a wide-range intrahelix π-π interaction, the optical resolution of [2,1][17]helicene was successfully achieved, and chiroptical properties such as circular dichroism and circularly polarized luminescence were elucidated for the first time as enantiomers of pristine [2,1][n]helicene core.
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1
Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
J Am Chem Soc
Año:
2023
Tipo del documento:
Article
País de afiliación:
Japón