A method of iridium-catalyzed hydroboration of isobutylene with pinacolborane (HBpin), characterized in that, it comprises the process steps of; I. attaching a flask containing 99.9999% pure Ar to a two-necked glass flask dried at 100-150°C and cooled at a room temperature under Ar gas, and cooling said glass flask first to room temperature and then to -60 °C, II. transferring isobutylene in liquid form into the cooled flask mentioned in the previous process step, from a tank having a bottom pipe system, by means of a silicone hose, III. cooling a two-necked flask with an argon balloon attached thereto that contains tetrahydrofuran dried with Na-ketyl to -20 °C, and transferring an amount of isobutylene at a 1-5 M concentration by means of a cooled syringe, IV. storing the obtained isobutylene solutions at -20 °C for use in the next process steps, V. adding 0.1-1 mmol of HBpin, 0.1-1 mL of Iridium N-heterocyclic carbene complex [IrCl] that is pre-prepared in dry THF, 0.5-2 mL of THF dried with Na-ketyl, and a magnet, respectively, to a thick-walled glass tube with a screw cap in a glove box containing nitrogen gas, VI. mixing said glass tube for 1-10 minutes at a room temperature after its cap is closed, VII. taking said glass tube out of the glove box and cooling it down to -20 °C, VIII. taking 1-5 mL of isobutylene cooled to -20 °C and adding it to said glass tube by a syringe, and thus 1-10 mmol of isobutylene is present in said glass tube, IX. removing the septum attached to the glass tube with a screw-cap, attaching the cap of the glass tube, mixing for 10-20 hours by placing it in an oil bath heated to 80-120°C and positioned on a magnetic stirrer, X. cooling the glass tube with a screw cap after the reaction time is completed, and removing the isobutylene gas in said glass tube in a fume cupboard, XI. adding dodecane used as internal standard to the tube by using a small amount of solvent, and completing the synthesis of isobutylboronic acid pinacol ester, which is an organoboron compound. I. attaching a flask containing 99.9999% pure Ar to a two-necked glass flask dried at 100-150°C and cooled at a room temperature under Ar gas, and cooling said glass flask first to room temperature and then to -60 °C, II. transferring isobutylene in liquid form into the cooled flask mentioned in the previous process step, from a tank having a bottom pipe system, by means of a silicone hose, III. cooling a two-necked flask with an argon balloon attached thereto that contains tetrahydrofuran dried with Na-ketyl to -20 °C, and transferring an amount of isobutylene at a 1-5 M concentration by means of a cooled syringe, IV. storing the obtained isobutylene solutions at -20 °C for use in the next process steps, V. adding 0.1-1 mmol of HBpin, 0.1-1 mL of Iridium N-heterocyclic carbene complex [IrCl] that is pre-prepared in dry THF, 0.5-2 mL of THF dried with Na-ketyl, and a magnet, respectively, to a thick-walled glass tube with a screw cap in a glove box containing nitrogen gas, VI. mixing said glass tube for 1-10 minutes at a room temperature after its cap is closed, VII. taking said glass tube out of the glove box and cooling it down to -20 °C, VIII. taking 1-5 mL of isobutylene cooled to -20 °C and adding it to said glass tube by a syringe, and thus 1-10 mmol of isobutylene is present in said glass tube, IX. removing the septum attached to the glass tube with a screw-cap, attaching the cap of the glass tube, mixing for 10-20 hours by placing it in an oil bath heated to 80-120°C and positioned on a magnetic stirrer, X. cooling the glass tube with a screw cap after the reaction time is completed, and removing the isobutylene gas in said glass tube in a fume cupboard, XI. adding dodecane used as internal standard to the tube by using a small amount of solvent, and completing the synthesis of isobutylboronic acid pinacol ester, which is an organoboron compound.