Synthesis, Resolution, Configurational Stability, and Properties of Cationic Functionalized [5]Helicenes

Article Article scientifique Article Synthesis, Resolution, Configurational Stability, and Properties of Cationic Functionalized [5]Helicenes eng 2020 author Marinova Maya Krasimirova 736174 author Pascal Simon 829235 author Guenee Laure 115015 author Besnard Céline 682138 author Shivachev Boris author Kostova Kalina author Villani Claudio author Franzini Roberta author Dimitrov Vladimir author Lacour Jérôme 0000-0001-6247-8059 99165 11908-11923 10.1021/acs.joc.0c01716 0022-3263 https://pubs.acs.org/doi/10.1021/acs.joc.0c01716 A straightforward approach to the synthesis of two different series of cationic [5]helicenes has been achieved including, in dioxa series, the possibility to introduce aromatic functional groups at the periphery of the helical structure. While photophysical study highlights that the introduction of aryl substituents at position 23 of the helical moieties has a negligible impact on the optical properties, styryl substituents allow a welcoming extension of the conjugation pathways. Finally, a red shift of the optical properties was evidenced upon introduction of nitrogen atoms in the helicene scaffold, leading to particularly good fluorescence efficiencies in the red domain for a helicenic dye. Detailed information on racemization kinetics was collected for the most stable species upon direct high-performance liquid chromatography (HPLC) resolution or, when configurational lability was too high, through VT-HPLC analysis on the chiral stationary phase (ΔG‡ values ranging from 85.0 to 137.1 kJ·mol–1 and above). Dewey 540 36 Département de chimie organique 141 false 760 Groupe Lacour Journal of Organic Chemistry 85 18 12f973c1-a2df-42f2-8d4b-c5bea582e20f Article (Published version) Restricted acs.joc.0c01716.pdf 2633163 application/pdf 9d9e8e95-ea82-4950-b51f-98e2b6378b60 Article (Accepted version) Public 5helicenes_JOC_acceptance.pdf 1413230 application/pdf openAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie organique

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Synthesis, Resolution, Configurational Stability, and Properties of Cationic Functionalized [5]Helicenes	Journal of Organic Chemistry			2020	398	576

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Marinova, Maya Krasimirova