A one-pot synthesis of 1,4-naphthoquinone-2,3-bis-sulfides catalysed by a commercial laccase

Oxidative C–S bond formation with aryl and alkyl thiols was catalysed under mild conditions in a reaction vessel open to air at pH 4.5 and 7.15 in the presence of a commercial laccase (Novozym 51003) and a co-solvent (DMF) to afford 1,4-naphthoquinone-2,3-bis-sulfides. The synthesis of 1,4-naphthoquinone-2,3-bis-sulfides from two different 1,4-naphthohydroquinone substrates was investigated with regard to pH and number of equivalents of the thiol.