Ruthenium‐Catalyzed CH Activation in Target Oriented Synthesis of Natural Products and Active Pharmaceutical Intermediates

Abstract In this article, some of the ruthenium‐catalyzed directed and nondirected CH activation led functionalizations, such as alkylation, alkenylation, arylation, and amidation, which have been elegantly applied in the synthesis of various natural products and active pharmaceutical intermediates (API), has been described. Along with this, the novel approaches like the transient directing group (TDG) and chiral transient directing group (CTDC) aided asymmetric synthesis of the key intermediates employed in a total synthesis have been also narrated. In the majority of the cases, readily available inexpensive and air tolerant [RuCl 2 ( p ‐cymene)] 2 and RuCl 3 · x H 2 O complexes were often employed as catalysts, thus providing the sustainable step economic strategies for natural products and APIs synthesis and as potential alternative to conventional methods.