The Preparation of Some 10-Substituted Phenoxazines¹

Organocatalyzed Atom Transfer Radical Polymerization: Perspectives on Catalyst Design and Performance

“…Phenothiazine derivatives have been investigated in medical and biological applications since the 1880s . For example, methylene blue is a popular histologic stain used in biological research that changes color due to electron transfer reactions involving the phenothiazine core structure .…”

A general route for synthesis of N-aryl phenoxazines via copper(i)-catalyzed N-, N-, and O-arylations of 2-aminophenols

“…Thus, the synthesis of triarylamines usually required refluxing the mixture of the reactants, catalyst and/or ligand in high boiling solvent (toluene, NMP or DMF) in the presence of a strong base (KO t Bu, NaO t Bu or LiNH 2 ). 8 However, when 2-aminophenols (4) were used as the substrates, their N-arylations could proceed with weak bases under ligand-free conditions. 9 As shown in Scheme 2, by using different ratios of 2-aminophenol (4a) and iodobenzene (3a), the desired diarylamine 7 or triarylamine 8 was synthesized in high yields.…”

“…Even worse, the most often used procedure for this N-arylation was established as early as in 1957, in which the toxic nitrobenzene was used as a solvent for producing high temperature. 4 Thus, it is necessary to develop a mild method for an efficient preparation of 2 to easily achieve the molecular diversity. (5), by which a series of the derivatives of 2 were prepared efficiently in one-flask.…”

Comprehensive Overview of Progress in Functionalization of 2‐Pyridone and 2, 4 ‐Dihydroxy Pyridine: Key Constituents of Vital Natural Products

“…Formation of direct C−N bond can be effected through traditional Cu catalyzed Ullmann type C−N bond formation [132] which requires employment of high temperature and stoichiometric amount of copper reagent. However, there is much progress now in the field of transition metal catalyzed N ‐arylation of pyridones, most significant is the copper catalyzed reactions.The history of C−N bond formation in presence of catalytic transition metals is as recent as 1997 when Ukita reported copper catalyzed N ‐arylation of 2‐hydroxy pyridines using copper halides, oxides and copper powder [133] .…”