Tetrabutylammonium iodide catalyzed hydroxylation of naphthoquinone derivatives with tert-butyl hydroperoxide as an oxidant

Abstract

We have developed an effective and environmentally benign procedure for the hydroxylation of naphthoquinone derivatives by using tetrabutylammonium iodide as a catalyst and tert-butyl hydroperoxide as an oxidant. This methodology provides a facile protocol for the synthesis of some new naphthoquinone-based hydroxylates in satisfactory yields and broad substrate scope. Based on this new protocol, the synthesis of the drug, parvaquone and lapachol, was achieved. Furthermore, based on the observations of control experiments and the results previously reported, we proposed a plausible mechanism for the hydroxylation of naphthoquinone derivatives.