Palladium-Catalyzed Site-Selective C-H Arylation of 2,2'-Bipyridine-6-carboxamides via a Rollover Cyclometalation Pathway.

The first example of Pd(II)-catalyzed arylation of 2,2'-bipyridine-6-carboxamides via a rollover cyclometalation pathway is reported. A diverse range of (hetero)aryl iodides could be directly coupled with various 2,2'-bipyridine-6-carboxamides in exclusive site-selectivity, which offers a distinct entry to arylated 2,2'-bipyridine-6-carboxamides. A preliminary mechanistic study supports the Pd(II)-rollover cyclometalation pathway.