Transition metals catalyzed C-C and C-O bonds formation: facile synthesis of flavans and benzoxepines

A simple and practical method has been developed based on intermolecular [Pd]-catalyzed C-C and an intramolecular [Cu]-catalyzed C-O bond formations for the synthesis of flavans and benzoxepines. Interestingly, the method is amenable for the synthesis of a wide variety of flavans and benzoxepines with dense functionalities on aromatic moieties. Significantly, flavans and benzoxepines are present as core/part-structures in many biologically active natural products.