Pd/C as Heterogeneous Catalyst for the Direct Arylation of (Poly)fluorobenzenes

Abstract : The potential of the heterogeneous catalyst 10 % Pd/C in the direct arylation of (poly)fluorobenzene derivatives with aryl bromides has been investigated. In general, high yields of biaryl derivatives were obtained by using tri-, tetra-, and pentafluorobenzenes, whereas mono- and difluorobenzenes exhibited poor reactivity. The regioselectivities of the arylation reactions were similar to those observed with homogeneous palladium catalysts. Both electron-withdrawing and -donating substituents, such as nitrile, nitro, acetyl, ester, trifluoromethyl, tert-butyl, methoxy, or methyl, on the aryl bromide were tolerated. Unexpectedly, tetrafluoro-substituted [1,1′-biphenyl]-4-ols were obtained from pentafluorobenzene at 150 °C due to a formal regioselective hydroxylation, whereas at lower temperatures the expected pentafluorobiphenyls were obtained. However, no C−F bond cleavage was observed with the other polyfluorobenzene derivatives. These arylation reactions were carried out with only 1 mol % Pd/C as the catalyst and KOAc as an inexpensive base. Therefore, this protocol represents a very attractive access to (poly)fluoro-substituted biphenyls in terms of cost, simplicity, and sustainable chemistry because the Pd/C catalyst can be easily removed at the end of the reaction, there is no contamination with phosphine ligand residues, and the major side-product of the reaction is KOAc⋅HBr.
Document type :
Journal articles
Complete list of metadatas

Cited literature [39 references]  Display  Hide  Download

https://hal-univ-rennes1.archives-ouvertes.fr/hal-02161848
Contributor : Laurent Jonchère <>
Submitted on : Friday, June 21, 2019 - 3:43:09 PM
Last modification on : Saturday, June 22, 2019 - 1:40:58 AM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : 2019-10-12

Please log in to resquest access to the document

Identifiers

Citation

S. Mao, X. Shi, Jean-François Soulé, H. Doucet. Pd/C as Heterogeneous Catalyst for the Direct Arylation of (Poly)fluorobenzenes. Chemistry - A European Journal, Wiley-VCH Verlag, In press, ⟨10.1002/chem.201900921⟩. ⟨hal-02161848⟩

Share

Metrics

Record views

18