O₂-Mediated Dehydrogenative Phenoxazination of Phenols

Abstract

Phenoxazines, in particular N-arylated phenoxazines, represent an increasingly important scaffold in the material sciences. Moreover, the oxygen-gas-mediated dehydrogenative phenochalcogenazination concept of phenols has been developed and exemplified for X = sulfur and recently for X = selenium and tellurium. The smallest chalcogen, X = oxygen, is herein exemplified with various functional groups under a likewise trivial oxygen atmosphere.

Aromatic Amine Catalysts for the O2-Mediated Cross-Dehydrogenative Phenothiazination Reaction?

“…This reaction, which we originally discovered in 2015, 25 is highly specific to phenothiazines and phenols, such that it is being increasingly utilized as a benchmark oxidative coupling reaction for the development of diverse new technologies. 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 We have likewise utilized it in order to quantify the performance of all redox catalysts investigated in the present article. The aim was to investigate how far one can go in terms of redox catalytic activity in the absence of any heavy-atom-containing additives such as tellurium.…”