acidboronate

Acidboronate is a term used in chemistry to describe boron-centered acid compounds related to boronic acids and their derivatives. The prototypical members are boronic acids of the form R-B(OH)2 and their esterified relatives, boronate esters R-B(OR')2, as well as the corresponding boronate anions RB(OH)3− that form under basic conditions. These species share a boron atom that behaves as a Lewis acid and can engage in reversible interactions with diols and other nucleophiles. The acidity of boronic acids in water is typically in the range of pKa around 8 to 9 for many aryl derivatives, though substituents can shift this value.

Chemical behavior and reactivity: In aqueous or mildly acidic media, boronic acids readily bind cis-diols to form boronate esters, a reaction that is reversible and pH-dependent. Under basic conditions, boronic acids deprotonate to boronate species such as RB(OH)3−, which can modify binding and reactivity. In synthetic chemistry, boronates serve as important boron-based nucleophiles in cross‑coupling reactions (notably Suzuki–Miyaura couplings) and their esters can undergo transesterification with diols, enabling dynamic covalent chemistry. The acid–base properties of acidboronates influence their catalytic activity and interactions in different media.

Applications: Acidboronate-containing compounds find use in chemical biology, materials science, and catalysis. They enable selective binding to sugars and other diols, reversible capture of target molecules, and the construction of responsive materials and sensors. In organic synthesis, boronic acids and boronate esters are valued for their versatility in bond-forming reactions and in metabolic or diagnostic contexts.

See also: boronic acid, boronate ester, Suzuki coupling, carbohydrate recognition.