Pyridines are a common moiety found in biologically active natural products and relevant pharmaceuticals. In particular, aryl substituted pyridines are found as a valuable structural motif to synthesize antibacterial and anticancer active compounds. Preferentially, we synthesized several 3,5-dibromo-2-substituted pyridines from 3,5-dibromo-2-hydroxy or amino pyridine.
Due to the different steric or electronic environment of two bromines of the synthesized starting material, we expected we could control the rate of the oxidative addition. Herein, we report the chemoselective Suzuki-Miyaura cross-coupling reactions for the synthesis of unsymmetrical 3,5-diaryl pyridine derivatives employing 3,5-dibromo-2-substituted pyridines and boronic acids. Furthermore, one-pot synthesis of unsymmetrical 3,5-diaryl substituted pyridines has been investigated. |