SYNTHETIC STUDIES VIA THE CROSS-COUPLING REACTION OF ORGANOBORON DERIVATIVES WITH ORGANIC HALIDES

Previously, we reported the palladium-catalyzed cross-coupling reaction of 1-alkenylboron compounds with various vinylic or aryl halides in the presence of base to provide corresponding coupling products in good yields, stereo- and regioselectively. The recent progress of such reactions is discussed. Most recently, it has been found that B-alkylorganoboranes react readily with vinylic halides or haloarenes in the presence of special palladium catalyst and base. Furthermore, even the most difficult cross-coupling of B-alkyl-9-BBN with alkyl iodides has been demonstrated to proceed smoothly to give coupling alkane derivatives in moderate yields under special conditions. Finally, it will be discussed that B-alkyl-9-BBN derivatives react with iodoalkanes under carbon monoxide atmosphere in the presence of potassium phosphate and a catalytic amount of Pd(PPh3)4, yielding unsymmetrical ketones in excellent yields. The reaction is extremely accelerated by irradiation of light.