Reaction of Blatter and Verdazyl Radicals with Arynes: Synthesis and Investigation of N-Chiral, Antiaromatic Triazines, and Tetrazinones.

Arynes are versatile building blocks in organic chemistry. In contrast to their extensively examined ionic reactivity, radical reactions with arynes remain scarcely explored. In this study, we present a novel radical annulation reaction of stable Blatter and verdazyl radicals with arynes, which offers access to polycyclic triazines and tetrazinones. The N2- and N4-annulated triazines derived from Blatter radicals exhibit distinct bending modes of the 8π-electron triazine ring, yet retain a certain degree of antiaromaticity despite their nonplanar geometries, as revealed by NICS and ACID calculations. Notably, the N2-annulated triazines feature a strongly pyramidalized nitrogen atom with N-chirality. Optical resolution yielded pure enantiomers, from which the configurational stability was assessed to determine the N-inversion barrier. Furthermore, one of the N2-annulated triazine derivatives displayed intense fluorescence, highlighting its potential as a scaffold for light-emitting materials, whereas H-cell cycling studies of the N4-annulated triazine derivatives demonstrated long-term stability of the redox process underscoring their utility for battery applications.