Disubstituted pyridines: The double-coupling approach

A one-pot procedure leading to disubstituted pyridines from the starting dibromopyridines is described. Key features include the ability to couple a range of aryl and even alkenylboronic acids at the 2,3 and/or 2,5 positions with excellent regiocontrol under a standard set of conditions. Further, isolated yields are greatly improved by the use of neutral alumina in place of silica for product purification. Finally, the intrinsic electronic bias of the pyridine ring can be overcome by using a bromoiodopyridine.