We have rationally designed a new class of alkyne‐tethered oximes and applied them in an unprecedented iron‐catalyzed radical relay protocol for the rapid assembly of a wide array of structurally new and interesting fused pyridines. This method shows broad substrate scope and good functional‐group tolerance and enabled the synthesis of several biologically active molecules. Furthermore, the fused pyridines could be diversely functionalized through various simple transformations, such as cyclization, C−H alkylation, and a click reaction. DFT calculation studies indicate that the reactions involve cascade 1,5‐hydrogen atom transfer, 5‐exo‐dig radical addition, and cyclization processes. Moreover, preliminary biological investigations suggest that some of the fused pyridines exhibit good anti‐inflammatory activity by restoring the imbalance of inflammatory homeostasis of macrophages in a lipopolysaccharide‐induced model.

By integration of iminyl radical-triggered 1,5-hydrogen atom transfer and (5+ +2) or (5+ +1) annulation processes, aseries of structurally novel and interesting azepine and spirotetrahydropyridine derivatives have been successfully prepared in moderate to good yields.T his method utilizes FeCl 2 as the catalyst and readily available oximes as five-atom units,w hile showcasing broad substrate scope and good functional group compatibility.The annulation products can be easily converted into many valuable compounds.M oreover,D FT calculation studies are performed to providesome insights into the possible reaction mechanisms for the (5+ +2) and (5+ +1) annulations.

We have rationally designed a new class of alkyne‐tethered oximes and applied them in an unprecedented iron‐catalyzed radical relay protocol for the rapid assembly of a wide array of structurally new and interesting fused pyridines. This method shows broad substrate scope and good functional‐group tolerance and enabled the synthesis of several biologically active molecules. Furthermore, the fused pyridines could be diversely functionalized through various simple transformations, such as cyclization, C−H alkylation, and a click reaction. DFT calculation studies indicate that the reactions involve cascade 1,5‐hydrogen atom transfer, 5‐exo‐dig radical addition, and cyclization processes. Moreover, preliminary biological investigations suggest that some of the fused pyridines exhibit good anti‐inflammatory activity by restoring the imbalance of inflammatory homeostasis of macrophages in a lipopolysaccharide‐induced model.

By integration of iminyl radical-triggered 1,5-hydrogen atom transfer and (5+ +2) or (5+ +1) annulation processes, aseries of structurally novel and interesting azepine and spirotetrahydropyridine derivatives have been successfully prepared in moderate to good yields.T his method utilizes FeCl 2 as the catalyst and readily available oximes as five-atom units,w hile showcasing broad substrate scope and good functional group compatibility.The annulation products can be easily converted into many valuable compounds.M oreover,D FT calculation studies are performed to providesome insights into the possible reaction mechanisms for the (5+ +2) and (5+ +1) annulations.