An umpolung strategy for rapid access to thermally activated delayed fluorescence (TADF) materials based on phenazine

Herein, Ag(I)-promoted regioselective intramolecular radical nucleophilic addition/rearrangement of 2-aryl diazaboroles has been accomplished for the first time to construct phenazine structures. This protocol is an umpolung strategy based on the classical electrophilic mechanism, and therefore, a reversed regioselectivity was observed, which provides an opportunity to prepare sterically hindered phenazines. The resulting thermally activated delayed fluorescence (TADF) materials based on phenazine exhibit emission bands from green to red with high quantum yields and moderate fluorescence lifetimes as solid films.

Automated summary

The regioselective intramolecular radical nucleophilic addition/rearrangement of 2-aryl diazaboroles promoted by Ag(I) has been achieved for the first time to construct phenazine structures. This novel protocol, based on a reversed regioselectivity mechanism, allows the preparation of sterically hindered phenazines, which exhibit emission bands from green to red with high quantum yields and moderate fluorescence lifetimes as solid films.