Lighting the way to carbon borylation: Boron substituents provide versatile reactivity, and their utility has been emerging in pharmaceutical contexts. Fawcett et al. show that visible light can induce replacement of carboxylic acid groups with boronate esters, which will ease their introduction into a wide variety of compounds. Once the acids are activated with phthalimide substituents, they can react with catecholborane dimers under illumination in amide solvents, with no need for catalysts or other additives. The reaction appears to proceed by radical chain propagation after photoinitiation. Science , this issue p. 283

This feature article discusses the range of stereospecific transformations available to enantioenriched boronic esters, and their applications in synthesis.