Formyl MIDA boronate. C${}_1$ building block enables straightforward access to $\alpha$-functionalized organoboron derivatives

Formyl MIDA boronate has been known to be an elusive type of acylboronate that has not been obtained to date. In this work, an approach to the one-pot preparation and chemical transformations of formyl MIDA boronate were developed to provide new types of $\alpha$-functionalized organoboron compounds. Among them are acylboronate reagents which present boron-substituted analogues of ynones and $\beta$-dicarbonyl compounds. The developed synthetic procedures, utilizing formyl MIDA boronate, are tolerant to diverse functional groups, making this reagent an advantageous C${}_1$ building block for extending the scope of organoboron chemistry. (© 2020 Wiley‐VCH GmbH)