A facile and green synthetic route to boronic acidesters utilizing mechanochemistry

A facile and environmentally benign method for the formation of boronic acid esters from corresponding boronic acids is reported. Simple grinding of a 1 : 1 mixture of the boronic acid (alkyl, aryl, or heteroaryl boronic acid) and the diol (pinacol or 2,2-dimethylpropane-1,2-diol) without a solvent gave the boronic acid esters. A subsequent simple work-up step gave the title compounds in excellent yield and purity.