Boronic esters are esters formed between a boronic acid and an alcohol.
The compounds can be obtained from borate esters by condensation with alcohols and diols. Phenylboronic acid can be selfcondensed to the cyclic trimer called triphenyl anhydride or triphenylboroxin.
Compounds with 5-membered cyclic structures containing the C–O–B–O–C linkage are called dioxaborolanes and those with 6-membered rings dioxaborinanes.