New pyridylboronic acids and their cross-coupling reactions

Abstract

The novel substituted pyridylboronic acids 2-bromo-5-pyridylboronic acid 92, 3-hromo-5- pyridylboronic acid 97, 2-chloro-5-pyridylboronic acid 103, 2-fluoro-5- pyridylboronic acid 108, 2-methoxy-5-pyridylboronic acid 123, 2-ethoxy-5- pyridylboronic acid 125, 2-medioxy-3-pyridylboronic acid 131, 3-bromo-6-methoxy-4- pyridylboronic acid 134, 3-chloro-6-methoxy-4-pyridylboronic acid 137 and 3-hromo-6- ethoxy-4-pyridylboronic acid 138 have been synthesised and shown to undergo palladium-catalysed Suzuki cross-coupling reactions with a vast variety of heteroaryl bromides to yield novel heteroarylpyridine derivatives.5-Formylfnran-2-boronic acid 170 has been synthesised and isolated and has been shown to undergo palladium-catalysed Suzuki cross-coupling reactions with a variety of heteroaryl bromides to yield novel heteroaryl substituted furyl derivatives. These derivatives have been shown to undergo efficient functionalisation by Wittig chemistry.