Three-Component Difunctionalization of Alkenes or Cyclopropanes Using 4-Cyanopyridine as Pyridylation Reagents

Pyridine cores are important heterocycles that exist in natural products, pharmaceuticals, and chiral ligands. Recently, radical-based 4-cyanopyridine has an effective approach for the synthesis of complex pyridines. In this review, we provide an overview of the recent development of multicomponent reactions using 4-cyanopyridine as pyridylation reagent for rapidly constructing complex molecules, including pyridine core. We systematically classified the recent literatures in the field based on bonding type, including C─C or C-heteroatom. This review aims to highlight the results of 4-cyanopyridine as a powerful pyridylation reagent for multicomponent reactions.