Synthesis of Substituted 4-Arylamino-1,2-naphthoquinones in One-Pot Reactions Using CotA-Laccase as Biocatalyst

An efficient and environmentally benign biocatalytic strategy for the synthesis of substituted 4-arylamino-1,2-naphthoquinones was developed, through a cross-coupling reaction in which the 1,2-naphthoquinone nucleus, formed in the biocatalytic process mediated by CotA-laccase from Bacillus subtilis, is the key synthetic intermediate. Electrochemical data and kinetic parameters were determined revealing a significant higher specificity of CotA-laccase for 4-amino-3-hydroxynaphthalene-1-sulfonic acid (AHNSA). This ability of CotA-laccase to discriminate between oxidisable aromatic amines allows the set-up of one-pot reactions in the presence of the enzyme, between AHNSA and a set of appropriate aromatic amines under mild reaction conditions. (Figure presented.).