Recent progress in the synthesis of pyridinylboronic acids and esters

Recent progress in the synthesis of (un)substituted pyridinylboronic acids and esters is reviewed. Five approaches to the synthesis of (un)substituted pyridinylboronic acids and esters are summarized: (1) halogen-metal exchange (HMe) and borylation, (2) metal-hydrogen exchange via directed ortho-metallation (DoM) followed by borylation, (3) palladium-catalyzed crosscoupling of halopyridines with tetraalkoxydiborane or dialkoxyhydroborane (4) iridium or rhodium catalyzed C-H or C-F borylation, and (5) [4+2] cycloadditions.