Palladium-catalyzed highly regioselective 2-arylation of 2,x-dibromopyridines and its application in the efficient synthesis of a 17β-HSD1 inhibitor

2,3- and 2,5-Dibromopyridines reacted with arylboronic acids, catalyzed by Pd(OAc)2/PPh3 in the presence of K2CO3 in CH3CN/MeOH (2:1) at 50 °C for 24 h, to afford 2-arylpyridines in good to high yields, while 2,4-dibromopyridine reacted with arylboronic acid pinacol esters, catalyzed by Pd(OAc)2/PPh3 in the presence of KOH in CH3CN at 70 °C for 24 h, to afford 2-arylpyridines in good to high yields. To expand this methodology, a 17β-HSD1 inhibitor was synthesized in good yield. [Display omitted]