Activation of fluorinated arenes using NHC-stabilized nickel(0) complexes: Selectivity and mechanistic investigations

Schaub T, Fischer P, Steffen A, Braun T, Radius U, Mix A (2008)
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 130(29): 9304-9317.

Journal Article | Published | English

No fulltext has been uploaded

Author
; ; ; ; ;
Abstract
The reaction of [Ni-2((i)Pr(2)Im)(4)(COD)] 1a or [Ni((i)Pr(2)Im)(2) (eta(2)-C2H4)] 1b with different fluorinated arenes is reported. These reactions occur with a high chemo- and regioselectivity. In the case of polyfluorinated aromatics of the type C6F5X such as hexafluorobenzene (X = F) octafluorotoluene (X = CF3) trimethyl(pentafluorophenyl)silane (X = SiMe3) or decafluorobiphenyl (X = C6F5) the C-F activation regioselectively takes place at the C-F bond in the para position to the X group to afford the complexes trans-[Ni((i)Pr(2)Im)(2)(F)(C6F5)] 2, trans-[Ni((i)Pr(2)Im)(2)(F)(4-(CF3)C6F4)] 3, trans-[Ni((i)Pr(2)Im)(2)(F)(4-(CF3)C6F5)] 4, and trans-[Ni((i)Pr(2)Im)(2)(F)(4-(CF3)C6F5)] 5. Complex 5 was structurally characterized by X-ray diffraction. The reaction of 1a with partially fluorinated aromatic substrates C6HxFy leads to the products of a C-F activation trans-[Ni((i)Pr(2)Im)(2)(F)(2-(C6F4)] 7, trans-[Ni((i)Pr(2)Im)(2)(F)(3,5-(C6F2H3)] 8, trans-[Ni((i)Pr(2)Im)(2)(F)(2,3-(C6F2H3)]9a and trans-[Ni((i)Pr(2)Im)(2)(F)(2,6-(C6F2H3)] 9b, trans-[Ni((i)Pr(2)Im)(2)(F)(2,5-(C6F2H3)] 10, and trans-[Ni((i)Pr(2)Im)(2)(F)(2,3,5,6-(C6F4H)] 11. The reaction of 1a with octafluoronaphthalene yields exclusively trans-[Ni((i)Pr(2)Im)(2)(F)(1,3,45,6,7,8-(C10F7)] 6a, the product of an insertion into the C-F bond in the 2-position, whereas for the reaction of 1b with octafluoronaphthalene the two isomers trans-[Ni((i)Pr(2)Im)(2)(F)(1,3,4,5,6,7,8-C10F7)] 6a and trans-[Ni((i)Pr(2)Im)(2)(F)(2,3,4,5,6,7,8-C10F7)] 6b are formed in a ratio of 11:1. The reaction of 1a or of 1b with pentafluoropyridine at low temperatures affords trans[Ni((i)Pr(2)Im)(2)(F)(4-C5NF4)] 12a as the sole product, whereas the reaction of 1b performed at room temperature leads to the generation of trans-[Ni((i)Pr(2)Im)(2)(F)(4-(C5NF4)] 12a and trans-[Ni((i)Pr(2)Im)(2)(F)(2-C5NF4)] 12b in a ratio of approximately 1:2. The detection of intermediates as well as kinetic studies gives some insight into the mechanistic details for the activation of an aromatic carbon-fluorine bond at the {Ni((i)Pr(2)Im)(2)} complex fragment. The intermediates of the reaction of 1b with hexafluorobenzene and octafluoronaphthalene, [Ni((i)Pr(2)Im)(2)(eta(2)-(C6F6)] 13 and [Ni((i)Pr(2)Im)(2)(eta(2)-C10F8)] 14, have been detected in solution. They convert into the C-F activation products. Complex 14 was structurally characterizd by X-ray diffraction. The rates for the loss of 14 at different temperatures for the C-F activation of the coordinated naphthalene are first order and the estimated activation enthalpy Delta H double dagger for this process was determined to be Delta H double dagger = 116 +/- 8 kJ mol(-1) (Delta S double dagger = 37 +/- 25 J K-1 mol(-1)). Furthermore, density functional theory calculations on the reaction of la with hexafluorobenzene, octafluoronaphthalene, octafluorotoluene, 1,2,4-trifluorobenzene, and 1,2,3-trifluorobenzene are presented.
Publishing Year
ISSN
eISSN
PUB-ID

Cite this

Schaub T, Fischer P, Steffen A, Braun T, Radius U, Mix A. Activation of fluorinated arenes using NHC-stabilized nickel(0) complexes: Selectivity and mechanistic investigations. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. 2008;130(29):9304-9317.
Schaub, T., Fischer, P., Steffen, A., Braun, T., Radius, U., & Mix, A. (2008). Activation of fluorinated arenes using NHC-stabilized nickel(0) complexes: Selectivity and mechanistic investigations. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 130(29), 9304-9317.
Schaub, T., Fischer, P., Steffen, A., Braun, T., Radius, U., and Mix, A. (2008). Activation of fluorinated arenes using NHC-stabilized nickel(0) complexes: Selectivity and mechanistic investigations. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 130, 9304-9317.
Schaub, T., et al., 2008. Activation of fluorinated arenes using NHC-stabilized nickel(0) complexes: Selectivity and mechanistic investigations. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 130(29), p 9304-9317.
T. Schaub, et al., “Activation of fluorinated arenes using NHC-stabilized nickel(0) complexes: Selectivity and mechanistic investigations”, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, vol. 130, 2008, pp. 9304-9317.
Schaub, T., Fischer, P., Steffen, A., Braun, T., Radius, U., Mix, A.: Activation of fluorinated arenes using NHC-stabilized nickel(0) complexes: Selectivity and mechanistic investigations. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. 130, 9304-9317 (2008).
Schaub, Thomas, Fischer, Peter, Steffen, Andreas, Braun, Thomas, Radius, Udo, and Mix, Andreas. “Activation of fluorinated arenes using NHC-stabilized nickel(0) complexes: Selectivity and mechanistic investigations”. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 130.29 (2008): 9304-9317.
This data publication is cited in the following publications:
This publication cites the following data publications:

29 Citations in Europe PMC

Data provided by Europe PubMed Central.

Fluoride, bifluoride and trifluoromethyl complexes of iridium(I) and rhodium(I).
Truscott BJ, Nahra F, Slawin AM, Cordes DB, Nolan SP., Chem. Commun. (Camb.) 51(1), 2015
PMID: 25358404
Titanium-catalyzed vinylic and allylic C-F bond activation-scope, limitations and mechanistic insight.
Kuehnel MF, Holstein P, Kliche M, Kruger J, Matthies S, Nitsch D, Schutt J, Sparenberg M, Lentz D., Chemistry 18(34), 2012
PMID: 22777749

Export

0 Marked Publications

Open Data PUB

Web of Science

View record in Web of Science®

Sources

PMID: 18588290
PubMed | Europe PMC

Search this title in

Google Scholar