204203-14-5Relevant articles and documents
Photolysis and thermolysis of bis(imino)pyridine cobalt azides: C-H activation from putative cobalt nitrido complexes
Hojilla Atienza, Crisita Carmen,Bowman, Amanda C.,Lobkovsky, Emil,Chirik, Paul J.
, p. 16343 - 16345 (2010)
A series of planar aryl-substituted bis(imino)pyridine cobalt azide complexes were prepared and evaluated as synthetic precursors for the corresponding cobalt nitrido compounds. Thermolysis or photolysis of two examples resulted in intramolecular C-H acti
Method for producing oligomer and catalyst
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Page/Page column 20, (2020/11/30)
The present invention provides a method for preparing an oligomer and a catalyst comprising a step of oligomerizing a polymerizable monomer containing an olefin in the presence of a catalyst, which comprises (A) a complex of a diimine compound and at leas
Mechanism of the Bis(imino)pyridine-Iron-Catalyzed Hydromagnesiation of Styrene Derivatives
Neate, Peter G. N.,Greenhalgh, Mark D.,Brennessel, William W.,Thomas, Stephen P.,Neidig, Michael L.
supporting information, p. 10099 - 10108 (2019/07/04)
Iron-catalyzed hydromagnesiation of styrene derivatives offers a rapid and efficient method to generate benzylic Grignard reagents, which can be applied in a range of transformations to provide products of formal hydrofunctionalization. While iron-catalyzed methodologies exist for the hydromagnesiation of terminal alkenes, internal alkynes, and styrene derivatives, the underlying mechanisms of catalysis remain largely undefined. To address this issue and determine the divergent reactivity from established cross-coupling and hydrofunctionalization reactions, a detailed study of the bis(imino)pyridine iron-catalyzed hydromagnesiation of styrene derivatives is reported. Using a combination of kinetic analysis, deuterium labeling, and reactivity studies as well as in situ 57Fe M?ssbauer spectroscopy, key mechanistic features and species were established. A formally iron(0) ate complex [iPrBIPFe(Et)(CH2a?CH2)]- was identified as the principle resting state of the catalyst. Dissociation of ethene forms the catalytically active species which can reversibly coordinate the styrene derivative and mediate a direct and reversible β-hydride transfer, negating the necessity of a discrete iron hydride intermediate. Finally, displacement of the tridentate bis(imino)pyridine ligand over the course of the reaction results in the formation of a tris-styrene-coordinated iron(0) complex, which is also a competent catalyst for hydromagnesiation.
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.
