Palladium-catalyzed direct reductive cross-coupling of aryltrimethylammonium salts with aryl bromides

An efficient palladium-catalyzed direct reductive cross-coupling of aryltrimethylammonium salts with aryl bromides was developed. The reactions proceeded smoothly in the presence of a palladium catalyst, magnesium turnings, LiCl, and TMEDA in THF at room temperature, leading to the corresponding biaryl compounds in moderate to good yields with reasonable functional group tolerance. The one-pot reaction using cheap and readily available aryl bromide as a coupling partner is simple to handle, thereby avoiding the use of pre-prepared organometallic reagents.