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Free keywords:
amination; C‒N activation; heterocycles; late-stage functionalization; pyrylium
Abstract:
The functionalization of aminoheterocycles via a pyrylium tetrafluoroborate reagent (Pyry‐BF4) is presented. This reagent efficiently condenses with a great variety of heterocyclic amines and primes the C‒N bond for nucleophilic aromatic substitution. More than 60 examples of C‒O, C‒N, C‒S or C‒SO2R are disclosed herein. In contrast to C‒N activation via diazotization and polyalkylation, this method is characterized by its mild conditions and impressive functional group tolerance. In addition to small molecule derivatization, Pyry‐BF4 allows for the introduction of functional groups in a late‐stage fashion to furnish highly functionalized structures.
