Mild Pd-Catalyzed Aminocarbonylation of (Hetero)Aryl Bromides with a

ABSTRACT: A palladacyclic precatalyst is employed to cleanly generate a highly active XantPhos-ligated Pd-catalyst. Its use in low temperature aminocarbonylations of (hetero)aryl bromides provides access to a range of challenging products in good to excellent yields with low catalyst loading and only a slight excess of CO. Some products are unattainable by traditional carbon-ylative coupling. Heterocycles are an important constituent in manypharmaceuticals.1 Transition metal catalysis plays a key role in the selective functionalization of heteroaromatic systems. Yet, many metal-catalyzed transformations suffer from the metal coordinating ability of heterocycles, resulting either in byproduct formation or inhibition of catalytic turnover.2 In many instances, specialized reaction conditions or catalyst systems are needed in order to provide reasonable yields of the desired products.3 Amides represent a ubiquitous functional group in pharma