Enantiopure [6]-Azairidahelicene by Dynamic Kinetic Resolution of a Configurationally Labile [4]-Helicene

Ariadna Pazos; Carlos M Cruz; Juan M Cuerva; Ivan Rivilla; Fernando P Cossío; Zoraida Freixa

doi:10.1002/anie.202406663

Enantiopure [6]-Azairidahelicene by Dynamic Kinetic Resolution of a Configurationally Labile [4]-Helicene

Angew Chem Int Ed Engl. 2024 Jun 21;63(26):e202406663. doi: 10.1002/anie.202406663. Epub 2024 May 24.

Authors

Ariadna Pazos¹, Carlos M Cruz², Juan M Cuerva², Ivan Rivilla^{3

4

5}, Fernando P Cossío^{4

5}, Zoraida Freixa^{1

3}

Affiliations

¹ Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country (UPV/EHU), 20018, Donostia, Spain.
² Department of Organic Chemistry, Unidad de Excelencia de Química (UEQ), Faculty of Sciences, University of Granada, Avda. Fuente Nueva s/n, 18071, Granada, Spain.
³ IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
⁴ Department of Organic Chemistry II, Faculty of Chemistry, University of the Basque Country (UPV/EHU), 20018, Donostia, Spain.
⁵ Donostia International Physics Center (DIPC), 20018, Donostia, Spain.

PMID: 38655628
DOI: 10.1002/anie.202406663

Abstract

A pair of enantiopure [6]-azairidahelicenes incorporating chirality at the metal center and on the helicenic ligand were synthesized by dynamic kinetic resolution (dkr) of a configurationally labile [4]-helicenic ligand (4-(2-pyridyl)-benzo[g]phenanthrene, L1H) using bis-cyclometalated chiral-at-metal only iridium(III) precursors as chiral inductors. The origin of the observed dkr is attributed to the different conformation and stability of diastereomeric reaction intermediates formed during the cyclometalation process. The isolated enantiomers exhibited circularly polarized phosphorescence (CPP), with |g_phos| values of 1.8×10^-3.

Keywords: Chiral-at-metal Complexes; Circularly Polarized Luminescence; Helical Structures; Iridium; Kinetic resolution.

Abstract

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