The Synthesis and Applications of Heterocyclic Boronic Acids

Abstract
Boronic acids are valued by organic chemists for their important role in the synthesis of biphenyls via a palladium(0) catalysed cross-coupling reaction with aryl halides (Suzuki reaction). Despite their synthetic utility and known biological activities heterocyclic boronic acids feature less frequently often due to difficulties in their synthesis. This paper provides an overview of the synthesis and applications of a range of heterocyclic boronic acids. 1 Introduction 2 Nitrogen Heterocycles 2.1 Pyridinylboronic Acids 2.1 1 2-Pyridinylboronic Acid 2.1 2 3- and 4-Pyridinylboronic Acid 2.2 Pyrrolylboronic Acids 2.2.1 Pyrrole-2-boronic Acid 2.2.2 Pyrrole-3-boronic Acid 2.3 Indolylboronic Acids 2.3.1 Indol-2-ylboronic Acid 2.3.2 Indol-3-ylboronic Acid 2.3.3 5/6/7-Indolylboronic Acid 2.4 Imidazolylboronic Acids 2.5 Quinolinylboronic Acids 2.6 Pyrimidinylboronic Acids 3 Sulfur Heterocycles 3.1 Thienylboronic Acids 3.1.1 2-Thienylboronic Acid 3.1.2 3-Thienylboronic Acids 3.2 Benzothiophenylboronic Acids 4 Oxygen Heterocycles 4.1 Furylboronic Acids 4.1.1 2-Furylboronic Acid 4.1.2 3-Furylboronic Acid 4.2 Benzofuranylboronic Acids 5 Conclusions