Oxidative C-S and C-C bond formation with aryl and alkyl thiols was catalyzed under mild conditions in a reaction vessel open to air at pH 4.5 in the presence of a commercial laccase (Novozym 51003 or Suberase) and a cosolvent (DMF) to afford 1,4-naphthoquinone sulfides. Although both monothiolation and dithiolation of the 1,4-naphthohydroquinone were accomplished, the latter was favored. In addition, unprecedented dimerization of monothiolated intermediates occurred through C-C coupling. These commercial laccases provide a facile and a more environmentally friendly synthetic approach to both 1,4-naphthoquinone sulfides and 1,4-naphthoquinone sulfide dimers.
Reference:
Wellington, K.W, Gordon, G.E.R, Ndlovu, L.A and Steenkamp, P. 2013. Laccase-catalyzed C-S and C-C coupling for a one-pot synthesis of 1,4-naphthoquinone sulfides and 1,4-naphthoquinone sulfide dimers. ChemCatChem, vol. 5(4), pp 1570–1577
Wellington, K. W., Gordon, G., Ndlovu, L., & Steenkamp, P. (2013). Laccase-catalyzed C-S and C-C coupling for a one-pot synthesis of 1,4-naphthoquinone sulfides and 1,4-naphthoquinone sulfide dimers. http://hdl.handle.net/10204/7131
Wellington, Kevin W, GER Gordon, LA Ndlovu, and P Steenkamp "Laccase-catalyzed C-S and C-C coupling for a one-pot synthesis of 1,4-naphthoquinone sulfides and 1,4-naphthoquinone sulfide dimers." (2013) http://hdl.handle.net/10204/7131
Wellington KW, Gordon G, Ndlovu L, Steenkamp P. Laccase-catalyzed C-S and C-C coupling for a one-pot synthesis of 1,4-naphthoquinone sulfides and 1,4-naphthoquinone sulfide dimers. 2013; http://hdl.handle.net/10204/7131.