One-pot synthesis of polycyclic pyridines through a Suzuki-Miyaura cascade reaction and cyclization sequence

Herein, we report an efficient one-pot strategy for the synthesis of seven-membered fused polycyclic pyridines from 3-(2-bromophenyl)-1,5-diphenylpentane-1,5-diones and 2-formylphenylboronic acids via a [Pd]-catalyzed domino reaction, followed by cyclization with ammonium acetate. Notably, the strategy was extended to 1-(2-iodophenyl)-3,5-diphenylpentane-1,5-diones thereby accessing diverse polycyclic pyridines. The salient features are facile operation, broad functional-group compatibility, and the effective construction of two C-C and two C-N bonds. Furthermore, a scale-up experiment and post-synthetic transformations were demonstrated.