This chapter describes the procedure for preparation of N ‐methyliminodiactic acid (MIDA) anhydride and reaction with boronic acids. It presents some of the important points to be considered, the conditions that need to be maintained, characterization data, and the reagents required, as well as the techniques used and the equipment setup that are vital to carrying out the process. The chapter also describes the hazards associated with working with chemicals and the ways to deal with these hazards. Boronic acids are amongst the most widely used reagents for the assembly of small organic molecules. The protection of boron with MIDA has broadly enabled the synthesis of many complex MIDA boronate building blocks using transformations otherwise incompatible with boronic acids. MIDA boronates possess an unusual binary affinity for silica gel.

<div> <div> <div> <p>Existing methods for making MIDA boronates require harsh conditions and complex procedures to achieve dehydration. Here we disclose that a pre-dried form of MIDA, MIDA anhydride, acts as both a source of the MIDA ligand and an in situ desiccant to enable a mild and simple MIDA boronate synthesis procedure. This method expands the range of sensitive boronic acids that can be converted into their MIDA boronate counterparts. Further utilizing unique properties of MIDA boronates, we have developed a MIDA Boronate Maker Kit which enables the direct preparation and purification of MIDA boronates from boronic acids using only heating and centrifuge equipment that is widely available in labs that do not specialize in organic synthesis. </p> </div> </div> </div>