Oxidative cross-coupling reactions of substituted o-aminophenols were catalyzed by a commercial laccase to produce non-symmetrically substituted phenoxazinones for the first time. Identification by 1H-, 13C- and 31P-NMR, and by HPLC-PDA and HPLC-MS/MS of exclusively two kinds of substituted phenoxazinones out of four potential heterocyclic frameworks was confirmed by a DFT study. The redox-properties of the substrates, their relative rates of conversion and the rigid docking of selected substrates led to a revisited mechanistic pathway for phenoxazinones biosynthesis. Our suggestions concern both the first formal two-electron oxidation by laccase and the first intermolecular 1,4-conjugated addition which secures the observed regioselectivity.
The present invention concerns highly water-soluble phenoxazines dyes of formula (I)
wherein R
1
, R
2
, R
3
, R
4
, R
5
and R
6
have the meaning defined in the claim, with improved photochemical properties, low toxicity, and favourable solubility in water. It also concerns a method for their preparation.
[EN] PHENOXAZINE DYES<br/>[FR] COLORANTS DE PHÉNOXAZINE
申请人:WETLANDS INCUBATOR SPRL
公开号:WO2010003970A2
公开(公告)日:2010-01-14
The present invention concerns highly water-soluble phenoxazines dyes of formula (I) wherein R1, R2, R3, R4, R5 and R6 have the meaning defined in the claim, with improved photochemical properties, low toxicity, and favourable solubility in water. It also concerns a method for their preparation.
Laccase-Mediated Synthesis of Novel Substituted Phenoxazine Chromophores Featuring Tuneable Water Solubility
oxidative coupling reactions. Yet, laccases remain rarely described as biocatalysts in organic synthesis. This paper describes the chemical preparation of original sulfonated aminophenol substrates and their enzyme‐mediated dimerisation into phenoxazinechromophores that featuretuneablewatersolubility as a function of the sulfonyl substituent. The scope and limitations of the biocatalysed synthetic