A Sustainable Synthesis of Asymmetric Phenazines and Phenoxazinones Mediated by CotA‐Laccase

Abstract

AbstractAn efficient and sustainable one‐step procedure for the synthesis of new asymmetric phenazines and phenoxazinones from commercially available ortho‐substituted diamines and ortho‐substituted hydroxyamines is reported. In this study we have expanded the substrate scope of CotA‐laccase‐catalyzed aerobic oxidations through the use of aromatic amines presenting variable functional groups, including N‐substitution, contributing to the rational synthesis of different heterocyclic scaffolds. The transformations proceed smoothly through a cascade of oxidative reactions to the benzoquinonediimine intermediates followed by nucleophilic addition, intramolecular cyclization and aromatization, all performed in mild conditions.magnified image