A Study On The Synthesis Of The Substituted Arylboronic Esters In Water Phase

Arylboronic esters and substituted arylboronic esters have been widely used in the fields of chemical, a series of biomedical, electronics, LCD, etc. Therefor, the efficient synthesis of arylboronic esters and substituted arylboronic esters was a popular research to synthetic organic chemists.In this study, substituted arylboronic esters were prepared from aryldiazonium tetrafluoroborate salts with bis(pinacolato)diboron using a catalytic amount of CuBr in acetonitrile/water at room temperature. As the solvent, acetonitrile/water was environment-friendly, CuBr is very cheap. The procedure was simple and convenient.The synthetic process was developed. The reaction parameters such as solvent, reaction temperature, catalyst and reaction time were optimized with the substitute of p-methyclopentanoe aryldiazonium tetrafluoroborate salts bis(pinacolato)diboron.A general procedure of optimizing the reaction condition is described as follows:1 equiv of aryldiazonium tetrafluoroborate salts are stirred for 3h with 1 equiv of bis(pinacolato)diboron and a 5mol% amount of CuBr in acetonitrile/water(3:1). Products were purified by flash column chromatography, the structures of products were characterized by MS and 1HNMR spectra.