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 Apr 24:e202406663. doi: 10.1002/anie.202406663. Online ahead of print.

Authors

Ariadna Pazos¹, Carlos M Cruz², Juan M Cuerva², Ivan Rivilla³, Fernando P Cossío³, Zoraida Freixa⁴

Affiliations

¹ University of the Basque Country - Gipuzkoa Campus, Applied Chemistry, SPAIN.
² University of Granada, Department of Organic Chemistry, SPAIN.
³ University of the Basque Country - Gipuzkoa Campus, Department of Organic Chemistry II, SPAIN.
⁴ Universidad del Pais Vasco, Homogeneous catalysis, Paseo Manuel Lardizábal 3, 20018, San Sebastián, 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 |gphos| values of 1.8×10-3.

Keywords: Chiral-at-metal Complexes; Helical Structures; Kinetic resolution; circularly polarized luminescence; iridium.