The regiodivergent C-H borylation of 2,5-disubstituted heteroarenes with bis(pinacolato)diboron was achieved by using iridium catalysts formed in situ from [Ir(OMe)(cod)]2 /dtbpy (cod=1,5-cyclooctadiene, dtbpy: 4,4'-di-tert-butyl-2,2'-bipyridine) or [Ir(OMe)(cod)]2 /2 AsPh3 . When [Ir(OMe)(cod)]2 /dtbpy was used as the catalyst, borylation at the 4-position proceeded selectively to afford 4-borylated products in high yields (dtbpy system A). The regioselectivity changed when the [Ir(OMe)(cod)]2 /2 AsPh3 catalyst was used; 3-borylated products were obtained in high yields with high regioselectivity (AsPh3 system B). The regioselectivity of borylation was easily controlled by changing the ligands. This reaction was used in the syntheses of two different bioactive compound analogues by using the same starting material.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.