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Stereoselective Syntheses, Structures, and Properties of Extremely Distorted Chiral Nanographenes Embedding Hextuple Helicenes
Author(s) -
Roy Myriam,
Berezhnaia Veronika,
Villa Marco,
Vanthuyne Nicolas,
Giorgi Michel,
Naubron JeanValère,
Poyer Salomé,
Monnier Valérie,
Charles Laurence,
Carissan Yannick,
HagebaumReignier Denis,
Rodriguez Jean,
Gingras Marc,
Coquerel Yoann
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201913200
Subject(s) - helicene , triphenylene , enantiopure drug , chemistry , diastereomer , steric effects , supramolecular chemistry , chirality (physics) , stereochemistry , molecule , aromaticity , enantioselective synthesis , crystallography , organic chemistry , physics , nambu–jona lasinio model , quantum mechanics , quark , catalysis , chiral symmetry breaking
We report a molecular design and concept using π‐system elongation and steric effects from helicenes surrounding a triphenylene core toward stable chiral polycyclic aromatic hydrocarbons (PAHs) with a maximal π‐distortion to tackle their aromaticity, supramolecular and molecular properties. The selective syntheses, and the structural, conformational and chiroptical properties of two diastereomeric large multi‐helicenes of formula C 90 H 48 having a triphenylene core and embedding three [5]helicene units on their inner edges and three [7]helicene units at their periphery are reported based on diastereoselective and, when applicable, enantiospecific Yamamoto‐type cyclotrimerizations of racemic or enantiopure 9,10‐dibromo[7]helicene. Both molecules have an extremely distorted triphenylene core, and one of them exhibits the largest torsion angle recorded so far for a benzene ring (twist=36.9°).