Biocatalysis with Baker's yeast: A green and sustainable approach for C–B bond cleavage of aryl/heteroarylboronic acids and boronate esters at room temperature

Abstract

This work shows the application of a cheap biocatalyst, Baker's Yeast, towards quick, water mediated, chemoselective, oxidative hydroxylation of aryl/heteroarylboronic acids and arylboronate esters at room temperature, in a metal and ligand free condition, without the addition of external base or acid. A total of eighteen (18) different types of aryl/heteroaryl boronic acids and arylboronate esters were studied for the applicability of this protocol and the resultant phenols were formed in excellent yields (85–97% isolated). The reaction procedure is easy to follow and takes place at room temperature (25-28 °C) and under weakly acidic conditions (pH ~ 6). Baker's Yeast is a fairly stable substrate, bearing considerably good shelf life. Commercially available Baker's Yeast is very cheap and is required in very less amount (5 mg per mmol of arylboronic acid). Thus, economic viability, easy availability of catalyst and ease of handling the reaction, make this an efficient and facile methodology for the synthesis of diversified phenols.