Transition-Metal-Catalyzed Regioselective C–H Borylation of ­Pyridines

Abstract

C−H borylation strategy has spurred intense research endeavors due to the high atom- and step-economy it represents and the broad utilities of the resulting organoboranes. Nevertheless, this powerful transformation has subjected to limited substrate scope and poor regioselectivity when it was applied to Lewis basic substrates (e.g., azines). The basic functionalities in substrates would coordinate to the metal centers, hindering the formation of products. Herein, we provide a brief overview of recent advances in transition-metal-catalyzed regioselective C−H borylation of pyridines. Moreover, attentions are paid to the latest contributions presenting remarkable regioselectivity.

Fast and Selective β-C–H Borylation of N-Heterocycles with a Supramolecular Iridium Catalyst: Circumventing Deactivation Pathways and Mechanistic Insights

“…Indeed, the newly created C–B bond is a readily transformable moiety toward the formation of carbon–carbon and carbon–heteroatom bonds by using well-established methodologies . Besides the use of rhodium, platinum, cobalt, nickel, or lanthanide catalysts, iridium catalysts are exceptionally active enough to tackle the functionalization of C–H bonds belonging to highly inert aliphatic and aromatic fragments without the requirement to introduce directing groups in the substrates . Consequently, the site-, regio-, and enantioselectivities of such reactions have been a challenging focus of research because the bond dissociation energies associated with discriminating those C–H bonds lie on a narrow range .…”