Kinetically Stable Boron‐Heteroatom Bonds

ABSTRACT Achieving kinetic stability of hydrolytically labile bonds remains a persistent goal of chemistry. The present study investigates the kinetic stability of boron‐heteroatom bonds in N ‐methyliminodiacetic acid (MIDA) boronates. The hemilabile nature of the ligand has enabled the synthesis of molecules that would otherwise be considered too hydrolytically labile. Depending on the structure, acid‐promoted migration of the boryl substituent was found to produce molecules with boron bound to nitrogen in different oxidation states. The formation of azidoboronate over aminoboronate is a particularly interesting consequence of kinetic stabilization and is at odds with the expectedly low‐energy path to nitrogen gas elimination. By focusing on the unusual stability of boron‐heteroatom bonds in different settings, this study contributes to the development of fundamental aspects of organoboron chemistry and offers a path to versatile building blocks that should find widespread utility in chemistry.