A Mild Method for Making MIDA Boronates

Abstract

We disclose that a predried form of methyliminodiacetic acid (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 laboratories that do not specialize in organic synthesis.

Progress, challenges and future directions of heterocycles as building blocks in iterative methodologies towards sequence-defined oligomers and polymers

“…Looking to the future of heterocycles in the SDM field, to the best of our knowledge, no reports exist demonstrating the use of cyclic boronic esters to produce SDMs. Cyclic boronic esters are ideal candidates for future investigations given their: long term stability, chemical orthogonality, 128 ease of synthesis, 129 commercial availability, and their facile transformation into amines, alcohols, thiols and halides. 130 Hence, in this section we will briefly outline their reactivity, and sketch potential future directions with illustrative examples focusing on pinacol (pin) and N-methyliminoacetic acid (MIDA) variants.…”

Regio- and sequence-controlled conjugated topological oligomers and polymers via boronate-tag assisted solution-phase strategy

“…Recently, we reported that the MIDA group could stabilize boron-containing polymers, and used them as a versatile approach for other organoboron compounds by post-polymerization transformations and for functionalized polymers by Suzuki–Miyaura coupling 48 . Interestingly, MIDA boronates showed significant differences in solubility compared with boronic acid and also an unusual binary affinity for silica gel, which enabled the rapid separation of MIDA boronate products 49 , 50 .…”

The dioxasilepanyl group as a versatile organometallic unit: studies on stability, reactivity, and utility

“…Because of this contradictory nature, neither stability nor reactivity is perfect. Specifically, it is still difficult to fully avoid undesired degradation of B(pin) units during the transformations of other functional groups, and therefore B(pin) is not desirable as an M. Tougher boron units such as MIDA boronate 3 and B(dan) 4 are known to be tolerant to diverse reaction conditions because of their respective stabilization of the boron centre by intramolecular coordination and electron-donating amino groups. The reactivity of such protected boron units is, in turn, sacrificed and it is usually difficult to directly transform these boron functionalities without deprotection, with the exception of a few cases.…”