A noncryogenic protocol for the synthesis of 2-substituted 3-thienylboronic acids and esters as well as 3-substituted 2-thienylboronic acids and esters has been developed. Electrophiles were introduced regiospecifically in the 2-position of 2, 3-dibromothiophene and in the 3-position of 2-bromo-3-iodothiophene by halogen-magnesium exchange followed by quenching with electrophiles. Palladium-catalyzed borylation of the 2, 3- ...