Ein Modell für Semimet‐Hämerythrin; NMR‐spektroskopischer Nachweis für die Lokalisierung der Ladung in Bis(μ‐carboxylato)‐(μ‐phenolato)dieisen(II,III)‐Komplexen in Lösung

Abstract

ZUSCHRIFTEN dung dieses partiell delokalisierten Anions wird die Spaltung der P-Ph-Bindung im zweiten Schritt, der zu 6 fiihrt, ausgeschlossen. Die Anionen von 6 lassen sich anhand ihrer tieffeldverschobenen 31P-NMR-Signale (6 = 152-206) und ihrer grolJen Kopplungskonstanten 'J(P,P) und 2J(P,H) von ca. 440 bzw. 37 Hz identifizieren; diese Merkmale sind charakteristisch fur Polyphospholid-Ionen [']. Als weiterer Nachweis diente die 6 b Synthese des 1,2-Diphosphaferrocens 7 aus 6 b. ExperimentellesAlle Reaktionen wurden unter Argon durchgefuhrt. Die Losungsmittel wurden mit Standardmethoden gereinigt uud getrocknet. Die Syuthesen der als Ausgangsverbindungen verwendeten Titanacyclobutene wurden nach Lit. [12,13] durchgefuhrt.

Multiple Aromatic Amination Mediated by a Diiron Complex

“…[10] When the complex 1 a [Fe 2 (L)(mpdp)(H 2 O)](ClO 4 ) 2 (mpdp = 1,3-benzenedipropionate; for L see Scheme 1 with X = H) is reacted with oxygen donors such as m-chloroperbenzoic acid or iodosyl arenes it mediates an intramolecular oxygen atom transfer to the pendant benzyl residue of the ligand forming the orthohydroxybenzyl complex 2 (Scheme 1, with Y = O, Z = H). [11] In addition, we showed that complex 1 b [Fe 2 (L')(mpdp)-(CH 3 OH)](ClO 4 ) 2 where the ligand bears a 2,6-dichlorobenzyl residue (Scheme 1, X = Cl) is able to catalyze the aziridination of various olefins and the sulfonamidation of thioanisole in good to excellent yields.…”

“…Herein we present a diiron complex that can mediate the quantitative intramolecular amination of a benzyl group of the ligand without contamination of hydroxylated product, and that this amination produces both mono and bis(tosylamine) derivatives.In the course of our biomimetic studies of iron centers in oxygenases, we developed mixed-valent Fe II Fe III complexes of hexadentate binucleating ligands. [10] When the complex 1 a [Fe 2 (L)(mpdp)(H 2 O)](ClO 4 ) 2 (mpdp = 1,3-benzenedipropionate; for L see Scheme 1 with X = H) is reacted with oxygen donors such as m-chloroperbenzoic acid or iodosyl arenes it mediates an intramolecular oxygen atom transfer to the pendant benzyl residue of the ligand forming the ortho-hydroxybenzyl complex 2 (Scheme 1, with Y = O, Z = H). [11] In addition, we showed that complex 1 b [Fe 2 (L')(mpdp)-(CH 3 OH)](ClO 4 ) 2 where the ligand bears a 2,6-dichlorobenzyl residue (Scheme 1, X = Cl) is able to catalyze the aziridination of various olefins and the sulfonamidation of thioanisole in good to excellent yields.…”

A Diiron(III,IV) Imido Species Very Active in Nitrene‐Transfer Reactions

“…Then both bridging and terminal binding modes of the N(H)Ts group were considered. Moreover, because in 1 the solvent binds in the position trans to the bridging phenoxide21, 22 whereas in the insertion product of the non‐chloroprotected ligand, the N‐benzyltosylate is bound in the cis position,13 we considered both cis and trans isomers for the calculations of 3 and 4 . First, we explored the tosylamido complex {Fe III Fe III ‐NHTs} 4 and observed that the terminal mode is clearly preferred, the bridging structure being about 23 kcal mol −1 higher.…”

Multiple Aromatic Amination Mediated by a Diiron Complex

“…In the course of our biomimetic studies of iron centers in oxygenases, we developed mixed‐valent Fe II Fe III complexes of hexadentate binucleating ligands 10. When the complex 1 a [Fe 2 (L)(mpdp)(H 2 O)](ClO 4 ) 2 (mpdp=1,3‐benzenedipropionate; for L see Scheme with X=H) is reacted with oxygen donors such as m ‐chloroperbenzoic acid or iodosyl arenes it mediates an intramolecular oxygen atom transfer to the pendant benzyl residue of the ligand forming the ortho ‐hydroxybenzyl complex 2 (Scheme , with Y=O, Z=H) 11.…”