Novel biomimetic oxidation of lapachol with H2O2 catalysed by a manganese(iii) porphyrin complex
Sónia M. G. Pires,Rodrigo De Paula,Mário M. Q. Simões,Artur M. S. Silva,M. Rosário M. Domingues,Isabel C. M. S. Santos,Maria D. Vargas,Vítor F. Ferreira,M. Graça P. M. S. Neves,José A. S. Cavaleiro
RSC Advances Pub Date : 09/23/2011 00:00:00 , DOI:10.1039/C1RA00578B
Abstract

The biomimetic oxidation of lapachol (1) using aqueous hydrogen peroxide as oxidant and chloro[5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrinatomanganese(III)] (Mn-Porph) as catalyst is described. A comparison between the obtained results and those described for the oxidation of lapachol using meta-chloroperoxybenzoic acid (m-CPBA) reveals, besides different reaction products, a completely different selectivity. Unlike the m-CPBA approach, where ortho-naphthoquinones are obtained, para-naphthoquinones are highly favoured when using Mn-Porph and H2O2. Moreover, a new lactone is isolated and characterized in the present work.

Graphical abstract: Novel biomimetic oxidation of lapachol with H2O2 catalysed by a manganese(iii) porphyrin complex