Palladium-Catalysed Direct Heteroarylation of Bromobenzylacetamide Derivatives: A Simple Access to Heteroarylated Benzylamine Derivatives

摘要

The palladium-catalysed direct arylation of bromobenzylacetamide derivatives using a wide variety of heteroaromatics gives a very simple access to heteroarylated benzylacetamides. 2-, 3- and 4-Bromobenzylacetamides present a very similar reactivity. In the presence of 2-subtituted furans, thiophenes, pyrroles, thia-zoles, or imidazoles a regioselective 5-arylation was observed. The reaction of benzoxazole gave the 2-arylated compounds; whereas 3,5-dimethylisoxazole gave the 4-arylated products. In most cases, the system using PdCl(C_3H_5)(dppb) as the catalyst, KOAc as the base, and DMAC as the solvent gave high yields of coupling products.