Saturday, May 5, 2007

Palladium-Catalyzed Benzene Arylation: Incorporation of Catalytic Pivalic Acid as a Proton Shuttle and a Key Element in Catalyst Design


Marc Lafrance and Keith Fagnou
J. Am. Chem. Soc., 2006, 128, 16496 -16497
Summary: C-H activation processes represent an important area of synthetic exploration since the starting materials required are less functionalized and potentially less expensive. A Pd-pivalic acid co-catalyst system has been utilized in the direct arylation of benzene and aryl bromides. Experimental and computational studies indicate that the pivalate anion is a key component in the palladation/C-H bond breaking event. Additionally, aryl chorides and iodides were found to be poor substrates.

8 examples: 55-85%

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