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A two-stepprotocol has been developed for the introduction ofcyanomethylene groups to metalated aromatics through the intermediacyof substituted isoxazoles. Apalladium-mediated cross-coupling reaction was used to introduce theisoxazole unit, followed by release of the cyanomethylene functionunder thermal or microwave-assisted conditions. The intermediate isoxazoleswere shown to be amenable to further functionalization prior to deprotectionof the sensitive cyanomethylene motif, allowing access to a wide rangeof aryl- and heteroaryl-substituted acetonitrile building blocks. [ABSTRACT FROM AUTHOR]

This communication describes a method for the nucleophilic radiofluorination of electron-rich arenes. The reaction involves the initial C(sp²)-H functionalization of an electron-rich arene with MesI(OH)OTs to form a (mesityl)(aryl)iodonium salt. This salt is then used in situ in a Cu-mediated radiofluorination with [18F]KF. This approach leverages the stability and availability of electron-rich arene starting materials to enable mild late-stage radiofluorination of toluene, anisole, aniline, pyrrole, and thiophene derivatives. The radiofluorination has been automated to access a 41 mCi dose of an 18F-labeled nimesulide derivative in high (2800 ± 700 Ci/mmol) specific activity. [ABSTRACT FROM AUTHOR]