Abstract
Boronic acids are essential building blocks used for the synthesis of bioactive molecules, the generation of chemical libraries and the exploration of structure-activity relationships. As a result, more than ten thousand boronic acids are commercially available. Medicinal chemists are therefore facing a challenge; which of them should they select to maximize information obtained by the synthesis of new target molecules. The present article aims to help them to make the right choices. The boronic acids used frequently in the synthesis of bioactive molecules were identified by mining several large molecular and reaction databases and their properties were analyzed. Based on the results a diverse set of boronic acids covering well the bioactive chemical space was selected and is suggested as a basis for library design for the efficient exploration of structure-activity relationships. A Boronic Acid Navigator web tool which helps chemists to make their own selection is also made available at https://bit.ly/boronics.
Content

Supplementary material
boronic acids
Set of 1586 boronic acids used frequently in synthesis of bioactive molecules together with their calculated molecular properties.
Supplementary weblinks
Boronic Acid Navigator Web Tool
A web tool allowing medicinal chemists and cheminformatics scientists to perform navigation in the chemical space of boronic acids.