Rapid and efficient access to secondary arylmethylamines

Article abstract of DOI:10.1002/chem.201200831

Ammoniomethyl trifluoroborates are very powerful reagents that can be used to access biologically relevant aryl- and heteroaryl-methylamine motifs via Suzuki-Miyaura cross-couplings. Until now, this method was limited to the production of tertiary and primary amines. The synthesis of a large array of secondary ammoniomethyltrifluoroborates has been achieved through a one step nucleophilic substitution reaction on the potassium bromomethyltrifluoroborate. Smooth cross-coupling conditions have been designed, based on the use of an aminobiphenyl palladium precatalyst, to couple these trifluoroborates efficiently with aryl bromides. This strategy offers a new way to access biologically relevant motifs and allows, with the previously developed methods, access to all three classes of aminomethylarenes. Secondary ammoniomethyltrifluoroborates can be easily synthesized by nucleophilic substitution on potassium bromomethyltrifluoroborate. These reagents have then been used in Suzuki-Miyaura cross-couplings with aryl bromides, offering an effective access to the aminomethylarene structural motif. This new method provides an interesting alternative to the reductive amination procedure (see scheme). Copyright