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.