Cobalt-Copper Catalyzed C(sp2) - N Cross Coupling of Amides or Nitrogenated Heterocycles with Styrenyl or Aryl Halides

An efficient C(sp2) - N cross coupling of cyclic and acyclic amides with styrenyl/aryl/heteroaryl halides catalyzed by cobalt acetylacetonate in combination with copper(I) iodide, has been achieved. A library of diversely substituted cyclic and acyclic enamides have been obtained in high yields by this procedure. The reaction is stereoselective producing (E)-enamides from trans-styrenyl halides and (Z)- products from cis-halides. This procedure has been successfully employed for the coupling of other N-heterocycles such as pyrazole, imidazole and triazole with aryl/styrenyl/heteroaryl halides to produce the corresponding N-coupled products. A probable mechanism has been suggested.