COA of Formula: C5H6BNO2In 2020 ,《Reactivity of Boronic Acids toward Catechols in Aqueous Solution》 appeared in Journal of Organic Chemistry. The author of the article were Suzuki, Yota; Kusuyama, Daisuke; Sugaya, Tomoaki; Iwatsuki, Satoshi; Inamo, Masahiko; Takagi, Hideo D.; Ishihara, Koji. The article conveys some information:
Fundamental information on the reactivities of boronic acids toward catechols in aqueous solution is required in all the fields dealing with boronic acid. However, comprehensive studies on reactivity are often hindered by so-called “”proton ambiguity,”” which makes it impossible for the rate constants of boronic acid and boronate ion to be determined sep. Herein, we set up two reaction systems without proton ambiguity: (1) Alizarin Red S and (2) Tiron with several boronic acids (RB(OH)2) with different pKa’s and performed kinetic and equilibrium studies on the reaction systems. It was shown that the logarithms of the rate constants of RB(OH)2 and its conjugate boronate ion (RB(OH)3-) decreased and increased linearly, resp., with increasing pKa of RB(OH)2 for both systems. Consequently, the reactivities of RB(OH)2 and RB(OH)3- were reversed at high RB(OH)2 pKa. It was also shown that the bulky o-substituents of phenylboronic acids retarded the backward reactions, resulting in enhancement of the formation constants of boronic acid-catechol esters. In the experiment, the researchers used many compounds, for example, Pyridin-3-ylboronic acid(cas: 1692-25-7COA of Formula: C5H6BNO2)
Pyridin-3-ylboronic acid(cas: 1692-25-7) belongs to pyridine. Pyridine and pyridine-derived structures are privileged pharmacophores in medicinal chemistry and an essential functionality for organic chemists. As the prototypical π-deficient heterocycle, pyridine illustrates distinctive chemistry as both substrate and reagent. COA of Formula: C5H6BNO2