This thesis is mainly concerned with the development and application of iron-catalyzed reactions for the synthesis of nitrogen-containing organic compounds. Oximes were synthesized by a novel iron-catalyzed nitrosation of olefins with tert-butyl nitrite and sodium borohydride. Succinimides and maleimides were prepared by employing an iron-catalyzed carbonylation of internal alkynes with ammonia as a key step. This efficient method was applied for the synthesis of natural products and interesting organic building blocks.