Direct Access to Acylated Azobenzenes via Pd-Catalyzed C-H Functionalization and Further Transformation into an Indazole Backbone

Azobenzenes were readily acylated at the 2-position through a Pd-catalyzed C-H functionalization from simple aromatic azo compounds and aldehydes in good yields. The obtained acylated azobenzenes could be efficiently converted into the corresponding indazole derivatives in nearly quantitative yields.