4733-21-5Relevant articles and documents
A Sustainable Synthesis of Asymmetric Phenazines and Phenoxazinones Mediated by CotA-Laccase
Sousa, Ana Catarina,Concei??o Oliveira,Martins, Lígia O.,Robalo, M. Paula
, p. 575 - 583 (2018)
An 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. (Figure presented.).
TEMPO-catalyzed electrochemical dehydrogenative cyclocondensation of: O -aminophenols: Synthesis of aminophenoxazinones as antiproliferative agents
Cai, Yun-Rui,Ji, Su-Hui,Ma, Zhi-Yuan,Shonhe, Chantale,Zhou, Jianmin
supporting information, p. 8566 - 8570 (2021/11/17)
The aminophenoxazinone core is widely prevalent in natural products, dyes and pharmaceutical molecules. We report here a TEMPO-catalyzed electrosynthetic method allowing the dehydrogenative cyclocondensation of o-aminophenols. This mild and sustainable method proceeds in the absence of stoichiometric oxidants and uses an easily available organo-electrocatalyst to access pharmaceutically valuable 2-aminophenoxazinones. Mechanistic studies indicate that the electrochemically generated TEMPO+ enables the oxidative radical homo-dimerization of o-aminophenols. The application of electrosynthesis provides an approach for the synthesis of pseudo-aminophenoxazinone alkaloids with improved structural diversification and bioactivities. This journal is
Waste minimized synthesis of pharmaceutically active compounds: Via heterogeneous manganese catalysed C-H oxidation in flow
Ferlin, Francesco,Luque Navarro, Pilar María,Gu, Yanlong,Lanari, Daniela,Vaccaro, Luigi
supporting information, p. 397 - 403 (2020/02/13)
Herein, we present our results on the development of a continuous flow protocol enabling the waste minimised synthesis of relevant pharmaceuticals and natural compounds. Heterogeneous manganese catalytic systems have been used in combination with molecular oxygen to promote the C-H oxidative coupling of 2-aminophenols, benzenetriols and o-phenylenediamines to access a variety of 2-aminophenoxazin-3-ones (2a-i) and related diaminophenazines (2j-k) and purpurogallin (2l) with minimal metal contamination. Making use of safe and green cyclopentyl methyl ether (CPME), this methodology allowed a fast synthesis of fully decorated molecular entities, preserving the stability of the heterogeneous catalyst which showed minimal metal leaching, with minimal waste production (low E-factor).