Efficient catalytic aryl amination of bromoarenes using 3-iminophosphine palladium(II) chloride

While pursuing the development of new hydroamination catalysts, a 3-iminophosphine palladium(II) chloride complex [(3IP)PdCl2] was synthesized that has subsequently proven to be an effective precatalyst for the aryl amination of bromoarenes. This (3IP)PdCl2 complex has been utilized in the catalytic aryl amination of both bromobenzene and bromopyridine derivatives, specifically yielding excellent activity in coupling reactions involving bromobenzene, 4-bromotoluene, and 2-bromopyridine. Using a standard set of catalytic conditions, many alkyl and aryl amines have been investigated as coupling partners in the aryl amination of bromoarenes. In general, secondary alkyl amines and ortho-substituted anilines proved to be the best substrates for this reaction, commonly giving quantitative conversion to products, while primary amines and other anilines gave only poor to moderate results. Catalytic screening data, product yields, and full characterization of isolated products are included.

Graphical abstractA 3-iminophosphine palladium(II) chloride complex is shown to be effective for the aryl amination of bromobenzene and bromopyridine derivatives with excellent activity in reactions involving bromobenzene, 4-bromotoluene, and 2-bromopyridine. Catalytic screening data, product yields, and full characterization of isolated products are included for reactions utilizing thirty-five alkyl and aryl amines.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A new aryl amination catalyst was synthesized. ► Aryl amination of bromobenzene derivatives was successful. ► Aryl amination of 2- and 3-bromopyridine was achieved. ► Trends in catalytic activity were analyzed.