Copper-Catalyzed C−H Oxygenation of Benzoxepine-4-carboxylates: Facile Synthesis and Photophysical Properties of Naphtho[2,1-d]oxazoles and Benzo[c]phenoxazines
التفاصيل البيبلوغرافية
العنوان:
Copper-Catalyzed C−H Oxygenation of Benzoxepine-4-carboxylates: Facile Synthesis and Photophysical Properties of Naphtho[2,1-d]oxazoles and Benzo[c]phenoxazines
An efficient, solvent-free, one-pot protocol was developed for the preparation of naphtho[2,1-d]oxazoles and benzo[c]phenoxazines by the C−H oxygenation of benzoxepine-4-carboxylates with benzylamines and anilines in the presence of Cu(OAc)2. The synthesis, UV/vis absorption, fluorescence emission and electrochemical properties have been studied for these heterocyclic compounds. The benzo[c]phenoxazines absorbed in the UV/vis in the range 449–461 nm and fluorescence emission in the range 562–627 nm. The nitro- and dimethyl-substituted benzo[c]phenoxazines had the most favorable fluorescence emission in these series of compounds (emission maxima at 627 and 603 nm with quantum yields Φf=0.51 and 0.37, respectively). The optical and electrochemical properties suggest that these compounds can act as electron-transporting materials for organic light-emitting diode applications.