New manganese β-polynitroporphyrins as particularly efficient catalysts for biomimetic hydroxylation of aromatic compounds with H2O2

Abstract

A series of Mn porphyrins bearing one to eight β-nitro substituents were synthesized in high yield in three steps by using a new general method for selective nitration of a Zn(meso-tetraarylporphyrin); this Mn porphyrin series exhibits a remarkably wide span of Mn(III)/Mn(II) redox potentials from −290 to + 1150 mV (vs. SCE), and the Mn porphyrins bearing one to five β-nitro groups are particularly good catalysts for hydroxylation of aromatic compounds with H₂O₂, with yields up to 98, 83, 80 and 12%, respectively for anisole, naphthalene, acetanilide and ethylbenzene.