Cu(II)-Mediated C-C/C-O Bond Formation via C-H/C-C Bond Cleavage: Access to Benzofurans Using Amide as a Traceless Directing Group

摘要

A copper-mediated synthesis of 2,3-disubstituted benzofurans with the assistance of an 8-aminoquinolyl auxiliary is described from readily available benzamides and benzoylacetonitriles. In this reaction, the C-C bond is successfully constructed via C-H activation, and C-O bond is subsequently formed at the original position of the amide group in a one-pot manner. The amide directing group is detached simultaneously under the reaction conditions through C-C bond cleavage. Surprisngly, the distinct isoquinolinone products can be achieved by changing the reaction conditions using ammonia as amine source.