Heme compound II models in chemoselectivity and disproportionation reactions

Abstract

Heme compound II models bearing electron-deficient and -rich porphyrins, [FeIV(O)(TPFPP)(Cl)]– (1a) and [FeIV(O)(TMP)(Cl)]– (2a), respectively, are synthesized, spectroscopically characterized, and investigated in the chemoselectivity and disproportionation reactions using cyclohexene as...

Radical reactions enabled by polyfluoroaryl fragments: photocatalysis and beyond

“…For example, oxo-complexes 107.1 and 107.2 , which are intermediates of catalytic oxidation, dramatically differ in the chemoselectivity of cyclohexene oxidation (Scheme 107). 238 The reason for this, apparently, is the different susceptibility of these complexes to disproportionation. It is facilitated for the electron-rich 107.1 , but is difficult for the electron-deficient oxo-complex 107.2 .…”

Metal ion-induced enhanced oxidation of organic contaminants by ferrate: a review

“…Iron (Fe) has a range of valence states (0, II, III, IV, V, and VI) (Sharma et al 2015a, b). Iron in low-valent oxidative forms, such as Fe(0), Fe(II), and Fe(III), has been applied in nanotechnology, medicine, biocatalysis, energy, and environmental remediation (Brillas 2022;El Kateb et al 2022;Gupta et al 2022;Hong et al 2022;Li et al 2021b). Among the high-valent iron species, Fe(IV) and Fe(V) are implicated in biological oxidation reactions (Sharma 2013a;Soler et al 2022;Zhang et al 2021c).…”

A Manganese Compound I Model with a High Reactivity in the Oxidation of Organic Substrates and Water

“…A Mn­(IV)-oxo porphyrin complex, [Mn IV (O)­(TDCPP)] ( 1 ), was synthesized by reacting [Mn III (TDCPP)­(Cl)] with S PhIO (5 equiv) in CH 2 Cl 2 at −10 °C (Scheme A) . Addition of HOTf (10 equiv) to a solution of 1 generated a green-colored intermediate, denoted as 2 , exhibiting a Soret band at 390 nm with a reduced intensity and the broad Q-band at 674 nm (Figure ; SI, Experimental Section); such spectral features of the Soret and Q-bands suggest that a Mn species bearing a porphyrin π-cation radical ligand was generated via a disproportionation process (Scheme A), as demonstrated in iron porphyrin and TAML systems. − 2 was also generated by reacting [Mn III (TDCPP)­(Cl)] with CAN (4 equiv) in the presence of HOTf in CH 2 Cl 2 at −10 °C (Scheme A, blue-colored reaction) (Figure S1). 2 reverted to 1 upon addition of base (e.g., tetramethylammonium hydroxide), and further addition of protons to the resulting solution of 1 regenerated 2 and Mn­(III) complexes (Figure S2).…”