[Fe(F₂₀TPP)Cl]‐Catalyzed Amination with Arylamines and {[Fe(F₂₀TPP)(NAr)](PhINAr)} Intermediate Assessed by High‐Resolution ESI‐MS and DFT Calculations

Abstract

Amination of CH bonds catalyzed by transition metal complexes via nitrene/imide insertion is an appealing strategy for CN bond formation, and the use of iminoiodinanes, or their in situ generated forms from 'PhI(OAc)2 +primary amides (such as sulfonamides, sulfamates, and carbamates)', as nitrogen sources for the amination reaction has been well documented. In this work, a 'metal catalyst+PhI(OAc)2 +primary arylamines' amination protocol has been developed using [Fe(F20 TPP)Cl] (H2 F20 TPP=meso-tetrakis(pentafluorophenyl)porphyrin) as a catalyst. This catalytic method is applicable for both intra- and intermolecular amination of sp(2) and sp(3) CH bonds (>27 examples), affording the amination products, including natural products such as rutaecarpine, in moderate-to-good yields. ESI-MS analysis and DFT calculations lend support for the involvement of {[Fe(F20 TPP)(NC6 H4 -p-NO2 )](PhI=NC6 H4 -p-NO2 )} + . intermediate in the catalysis.

Elusive Reaction Intermediates in Solution Explored by ESI‐MS: Reverse Periscope for Mechanistic Investigations

“…Another cationic complex, which includes an iron(IV) ion has been intercepted as ap utative intermediate of the nitrene/imide insertion and transfer reaction using arylamines. [54] In ar ecent contribution from our group,w ei nvestigated the copper-catalyzed azide alkyne cycloaddition (CuAAC) by offline ESI-MS(/MS).…”

“…Another cationic complex, which includes an iron(IV) ion has been intercepted as ap utative intermediate of the nitrene/imide insertion and transfer reaction using arylamines. [54] In ar ecent contribution from our group,w ei nvestigated the copper-catalyzed azide alkyne cycloaddition (CuAAC) by offline ESI-MS(/MS). [2e] Its challenging mechanism had been previously addressed by several theoretical and experimental studies,w hich suggested am echanism involving binuclear copper intermediates.W et hen analyzed two different CuAACr eaction mixtures,o ne containing classic neutral reactants and the second containing imidazolium-based charged alkyne.T he approach, in both cases,a llowed, for the first time,i nterception and full characterization of the crucial bis(copper) intermediates like bis(copper) acetylides and triazoles (Figure 12).…”

Elektrospray‐Massenspektrometrie: ein umgekehrtes Periskop zur Erforschung von Reaktionsmechanismen in Lösung

“…Insbesondere der Eisen(IV)‐Komplex, der die Fe=O‐Einheit enthält, wurde als katalytisch effektiv identifiziert. Ein weiterer kationischer Komplex mit dem Eisen(IV)‐Ion wurde als mögliche Zwischenstufe bei der Nitren/Imid‐Insertion und der weiteren Übertragung mit Arylamiden abgefangen …”

Synthesis and catalytic activity of μ-oxo ruthenium(IV) porphyrin species to promote amination reactions

“…The development of efficient synthetic procedures to attain aminated compounds is of paramount importance due to pharmaceutical and/or biologic behaviours of aza-containing molecules. [1] Amongst all the catalysts capable of promoting amination reactions, ruthenium(II) porphyrin complexes [2][3][4] show a good efficiency in catalysing the amination of saturated and unsaturated hydrocarbons by using different classes of aminating agents such as aryl iminoiodinanes (RN=IAr) [5], amines in the presence of oxidant species [6] and organic azides (RN 3 ) [7][8][9][10][11]. Numerous structural modifications of the porphyrin skeleton were carried out to improve the catalytic performance which can also be modulated by the electronic nature of the axial ligands onto the ruthenium(II) centre [12,13].…”