2D-NMR and EPR study of the activation of π-allyl group within the coordination sphere of the imine–amide complex of nickel(II) by the coordination of PMe

Kraikivskii, P. B.; Saraev, V. V.; Meusinger, Reinhard; Bocharova, V. V.; Ushakov, Igor А.; Petrovskii, S. K.

doi:10.1016/j.jorganchem.2012.05.035

Cited by 5 publications

(4 citation statements)

References 15 publications

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“…Subsequent hydrogen-atom abstraction by a second equivalent of AgF 2 from 7 would then form two equivalents of AgF and one equivalent of HF (39). Alkyl and allyl, acyl, silyl, and amido complexes of several metal complexes are known to add across the C=N bond of pyridines, including those of Ni and Cu (40)(41)(42)(43) at or below room temperature. To determine if the analogous product from reaction of pyridine with AgF 2 lies at an accessible energy, we computed the relative ground-state energies of the pyridine-AgF 2 coordination complex (Fig.…”

Section: Reportsmentioning

confidence: 99%

Selective C-H Fluorination of Pyridines and Diazines Inspired by a Classic Amination Reaction

Fier

Hartwig

2013

Science

232

144

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Fluorinated heterocycles are prevalent in pharmaceuticals, agrochemicals, and materials. However, reactions that incorporate fluorine into heteroarenes are limited in scope and can be hazardous. We present a broadly applicable and safe method for the site-selective fluorination of a single carbon-hydrogen bond in pyridines and diazines using commercially available silver(II) fluoride. The reactions occur at ambient temperature within 1 hour with exclusive selectivity for fluorination adjacent to nitrogen. The mild conditions allow access to fluorinated derivatives of medicinally important compounds, as well as a range of 2-substituted pyridines prepared by subsequent nucleophilic displacement of fluoride. Mechanistic studies demonstrate that the pathway of a classic pyridine amination can be adapted for selective fluorination of a broad range of nitrogen heterocycles.

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Section: Reportsmentioning

confidence: 99%

Selective C-H Fluorination of Pyridines and Diazines Inspired by a Classic Amination Reaction

Fier

Hartwig

2013

Science

232

144

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“…These results draw attention to the possibility of Ni(0)/Ni(II) catalytic cycle; however, the involvement of Ni(I)/Ni(III) in the catalytic cyclic cannot be excluded since the recent literature provides evidence for the formation of transient Ni(I) species via comproportionation of Ni(0) and Ni(II) species − or disproportionation of Ni(II) species . Moreover, the pre-Ni(I) complex 4d also afforded the cross-coupled product 3a albeit in lower yield (Table ).…”

Section: Introductionmentioning

confidence: 87%

“…Order of 1.2, 1.1, and 1.1 was found for the catalyst 4a, alkyl ether 1a, and Grignard 2a, implying that they are involved in the rate-limiting step (Figure 2). 46 Moreover, the pre-Ni(I) complex 4d also afforded the crosscoupled product 3a albeit in lower yield (Table 1). Further support was accessed from CV experiments.…”

Section: ■ Introductionmentioning

confidence: 98%

Attenuation of Ni(0) Decomposition: Mechanistic Insights into AgF-Assisted Nickel-Mediated Silylation

et al. 2022

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In nickel-mediated Kumada cross-coupling reactions, low valent active nickel complexes are often generated in situ and the ligands usually govern the reactivity or stability of these complexes. However, the decomposition of active nickel complexes is inevitable if the subsequent reaction is sluggish. While we recently developed AgF-assisted nickel catalysis to cross-couple methyl ethers and silylmagnesium reagents, the intriguing catalytic role of AgF and the actual active nickel species remains elusive. Recently, both Ni(0) and Ni(I) intermediate complexes are identified as active species in Kumada cross-coupling reactions. Control experiments in combination with 31 P nuclear magnetic resonance (NMR) suggest that AgF attenuates the decomposition of in situ generated Ni(0) species. The plausible Ni(0) and Ni(I) intermediate complexes were synthesized, and experimental findings are consistent with the actual catalytic cycle being Ni(0)/Ni(II) rather than Ni(I)/Ni(III).

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“…The initial transmetalation step between the [Ni(II)] complex and the ArB(OH) 2 would lead to the [Ni]–Ar intermediate A . Complexation of A with the allenamide would trigger the regioselective insertion of the Ni–Ar bond into the CC of the allenyl unit ( B ) providing the allylic-Ni intermediate C with concomitant transfer of the aryl unit at the central carbon atom of the π-system …”

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confidence: 99%

Nickel-Catalyzed Synthesis of Stereochemically Defined Enamides via Bi- and Tricomponent Coupling Reaction

et al. 2017

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The stereoselective synthesis of (E)-trisubstituted tertiary enamides is documented via site-selective Ni-catalyzed β-arylation of allenamides with boronic acids in high yields (up to 89%). The nucleophilic character of the "organo-Ni" intermediates is further exploited to implement a one-pot tricomponent procedure involving the final allylation of aldehydes (yields up to 93%). Mechanistic insights and efficiency on a gram scale process were also documented.

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2D-NMR and EPR study of the activation of π-allyl group within the coordination sphere of the imine–amide complex of nickel(II) by the coordination of PMe

Cited by 5 publications

References 15 publications

Selective C-H Fluorination of Pyridines and Diazines Inspired by a Classic Amination Reaction

Selective C-H Fluorination of Pyridines and Diazines Inspired by a Classic Amination Reaction

Attenuation of Ni(0) Decomposition: Mechanistic Insights into AgF-Assisted Nickel-Mediated Silylation

Nickel-Catalyzed Synthesis of Stereochemically Defined Enamides via Bi- and Tricomponent Coupling Reaction

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