Five-membered rings with two adjacent heteroatoms with at least one boron

Developments in the chemistry of five-membered ring heterocycles containing two adjacent heteroatoms, with at least one boron, in the period 2008–2020 are reviewed. Application of theoretical and structural methods to these compounds is described including X-ray structure determination and both 11B and 31P NMR. The major reactions of azaboroline and phosphaborolane systems as well as their benzo analogues are discussed. Reactions and applications of benzoxaborolols have been extensively investigated related to the medicinal activity of these compounds. Chemistry of 1,2-diborole compounds has also developed significantly Methods for the synthesis of all the compounds are systematically covered. Most of the systems containing boron and phosphorus have only been reported recently and were not included in previous editions of Comprehensive Heterocyclic Chemistry.