Increasing rates and scope of reactions: Sluggish amines in microwave-heated aminocarbonylation reactions under air

Commercially available molybdenum hexacarbonyl serves as a convenient and solid carbon monoxide source in palladium-catalyzed aminocarbonylations of aryl bromides and iodides. This improved microwave protocol, relying on DBU as base and THIP as solvent, enables rapid couplings using otherwise sluggish anilines, tert-butylamine, and free amino acids. In addition, Cr(CO)(6) and W(CO)(6) were found to be useful alternative CO releasing reagents. Altogether, 16 different aromatic amides were synthesized under air in 35-95% yield after only 15 min of controlled microwave irradiation.