Synfacts 2013; 9(12): 1325
DOI: 10.1055/s-0033-1340140
Metal-Mediated Synthesis
© Georg Thieme Verlag Stuttgart · New York

Fluorination of Aryl Trifluoroborates

Contributor(s):
Paul Knochel
,
Andreas K. Steib
Mazzotti AR, Campbell MG, Tang P, Murphy JM, Ritter T * Harvard University, Cambridge, USA
Palladium(III)-Catalyzed Fluorination of Arylboronic Acid Derivatives.

J. Am. Chem. Soc. 2013;
135: 14012-14015
Further Information

Publication History

Publication Date:
18 November 2013 (online)

 

Significance

An air- and moisture-stable terpyridyl–palladium(II) precatalyst is found to be very ­active in the catalytic fluorination of aryl trifluoro­borates. This palladium-catalyzed fluorination reaction is also applicable to other common aryl­boronic acids such as pinacol boronic esters, boronic acids, or MIDA esters via in situ formation of the respective aryl trifluoroborates with NaF and KH2F.


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Comment

The authors propose a single electron transfer (SET) mechanism involving a palladium(III) intermediate. First, oxidation of the palladium(II) precatalyst by Selectfluor affords a palladium(III) intermediate and a Selectfluor radical cation. F transfer from the Selectfluor radical cation to the aryl trifluoroborate forms the C–F bond and a delocalized radical. SET from the radical to the palladium(III) intermediate generates the starting palladium(II) species and releases the aryl fluoride product as well as BF3.


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