Diazaborines oxidize slowly with HO but rapidly with peroxynitrite in aqueous buffer.

Reactive oxygen species (ROS) such as hydrogen peroxide (HO) and peroxynitrite (ONOO) oxidize arylboronic acids to their corresponding phenols. When used in molecular imaging probes and in ROS-responsive molecules, however, simple arylboronic acids struggle to discriminate between HO and ONOO because of their fast rate of reaction with both ROS. Here, we show that diazaborines (DABs) react slowly with HO but rapidly with peroxynitrite in an aqueous buffer.