799270-30-7Relevant academic research and scientific papers
Direct Observation of Transmetalation from a Neutral Boronate Ester to a Pyridine(diimine) Iron Alkoxide
Chirik, Paul J.,Peterson, Paul O.,Rummelt, Stephan M.,Stieber, S. Chantal E.,Wile, Bradley M.,Zhong, Hongyu
, (2020/01/11)
Transmetalation of the neutral boronate esters, (2-benzofuranyl)BPin and (2-benzofuranyl)BNeo (Pin = pinacolato, Neo = neopentylglycolato), to a representative pyridine(diimine) iron alkoxide complex, (iPrPDI)FeOEt (iPrPDI = 2,6-(2,6-iPr2-C6H3Na? CMe)2C5H3N; R = Me, Et, SiMe3), to yield the corresponding iron benzofuranyl derivative was studied. Synthesis of the requisite iron alkoxide complexes was accomplished either by salt metathesis between (iPrPDI)FeCl and NaOR (R = Me, Et, SiMe3) or by protonation of the iron alkyl, (iPrPDI)FeCH2SiMe3, by the free alcohol R′OH (R′ = Me, Et). A combination of magnetic measurements, X-ray diffraction, NMR, and M?ssbauer spectroscopies and DFT calculations identified each (iPrPDI)FeOR compound as an essentially planar, high-spin, S = 3/2 compound where the iron is engaged in antiferromagnetic coupling with a radical anion on the chelate (STotal = 3/2; SFe = 2, SPDI =-1/2). The resulting iron benzofuranyl product, (iPrPDI)Fe(2-benzofuranyl), was characterized by X-ray diffraction and in combination with magnetic measurements, spectroscopic and computational data, was identified as an overall S = 1/2 compound, demonstrating that a net spin-state change accompanies transmetalation (SFe = 1, SPDI =-1/2). These findings may be relevant to further development of iron-catalyzed Suzuki-Miyaura cross-coupling with neutral boronate esters and alkoxide bases.
Tandem C-H activation/arylation catalyzed by low-valent iron complexes with bisiminopyridine ligands
Salanouve, Elise,Bouzemame, Ghania,Blanchard, Sebastien,Derat, Etienne,Desage-El Murr, Marine,Fensterbank, Louis
supporting information, p. 4754 - 4761 (2014/05/06)
Tandem C-H activation/arylation between unactivated arenes and aryl halides catalyzed by iron complexes that bear redox-active non-innocent bisiminopyridine ligands is reported. Similar reactions catalyzed by first-row transition metals have been shown to involve substrate-based aryl radicals, whereas our catalytic system likely involves ligand-centered radicals. Preliminary mechanistic investigations based on spectroscopic and reactivity studies, in conjunction with DFT calculations, led us to propose that the reaction could proceed through an inner-sphere C-H activation pathway, which is rarely observed in the case of iron complexes. This bielectronic noble-metal-like behavior could be sustained by the redox-active non-innocent bisiminopyridine ligands. A radical choice! A low-valent iron complex with non-innocent bisiminopyridine ligands performs C-H activation/arylation of unactivated aryl compounds (see figure). The reaction likely involves ligand-based radicals, whereas previously reported iron-based systems imply substrate-based radicals.
HYDROSILYLATION CATALYSTS
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Page/Page column 23-24, (2011/02/24)
Disclosed herein are manganese, iron, cobalt, or nickel complexes containing terdentate pyridine diimine ligands and their use as efficient and selective hydrosilylation catalysts.
Highly active iron and cobalt catalysts for the polymerization of ethylene [18]
Small,Brookhart,Bennett
, p. 4049 - 4050 (2008/10/08)
Using the previously examined Ni(II) and Pd(II) α-diimine catalysts as a guide, new iron(II) and cobalt(II) catalysts based on tridentate pyridine bis-mine ligands were prepared. The resulting catalysts are robust and extremely active for polymerization of ethylene to linear, high-density polyethylene.
