Bring on the boron

Abstract

Boron—the beloved oddball of the periodic table—can do some unique chemistry, thanks to its empty p orbital. This has made boronic acids and boronate esters indispensable components in many compounds, such as in partners for Suzuki cross-coupling reactions, in polymers, and even in a few drugs, such as the cancer therapies bortezomib (Velcade) and ixazomib (Ninlaro). But, while there are a few ways to make boronic acids and boronate esters, none is trivial. Phil S. Baran’s group at Scripps Research Institute California, has now come up with a simple and practical method for converting carboxylic acids into boronate esters and boronic acids (Science 2017, DOI: 10.1126/science.aam7355). The method works on primary, secondary, and tertiary carboxylic acids, as well as with peptidic and even natural product-derived substrates. It also tolerates a broad range of functional groups, so it can be used in the final steps of the synthesis of a densely