Substituted five-membered heterocycles have attracted great interest over the past years due to their presence in a large number of pharmaceuticals and natural products.  Recently, an advance in the preparation of aryl-substituted heterocycles was achieved when the C-H activation method was reported, although sometimes poor regioselectivity was observed. While utilizing this reaction, we found that a variety of heterocyclic carboxylic acids can be employed as partners to obtain a regiospecific cross-coupling reaction.

This novel coupling is applicable to a wide range of heterocycles with yields varying from 19 – 88%. The scope and limitations of this reaction will be discussed.