DiazaChrysenes (DC): Nitrogen-Containing π-Extended Molecules for Photocatalytic C–H Amination
Wei Xu, Atsushi Iwai, Itsuki Nagasaka, Satsuki Watanabe, Ryosuke Tsutsumi, Naoya Kumagai
Abstract
We report a new class of nitrogen-containing π-extended heterocycles, DiazaChrysenes ( DC s), and their dimeric analogues ( dDC s) as metal-free photocatalysts for C–H amination. DC s featuring a quinolino[1,2- c ]quinazolin-5-ium core were synthesized via electrophilic amide activation and arylation. The resulting compounds displayed tunable photophysical and redox properties, with CF 3 -substituted DC s enabling the C–H amination of arenes with azoles under visible light and aerobic conditions, achieving yields up to 85%. The reaction tolerated a range of arene and azole substrates without requiring metal salts or additives. In contrast, dDC s exhibited diminished activity, likely due to their extended π-curvature. Computational studies, including NCI, ACID, and NICS analyses, revealed locally aromatic but electronically isolated π-systems and deshielded central 8-membered cores. This work highlights the utility of DC scaffolds as synthetically accessible and redox-tunable organic photocatalysts.