Catalyst-Switchable Regiocontrol in the Direct Arylation of Remote CH Groups in Pyrazolo[1,5-<i>a</i>]pyrimidines
作者:Robin B. Bedford、Steven J. Durrant、Michelle Montgomery
DOI:10.1002/anie.201502150
日期:2015.7.20
The regiodivergent palladium‐catalyzed CH arylation of pyrazolo[1,5‐a]pyrimidine has been achieved, wherein the switch in regioselectivity between positionsC3 and C7 is under complete catalyst control. A phosphine‐containing palladium catalyst promotes the direct arylation at the most acidic position (C7), whereas a phosphine‐free catalyst targets the most electron‐rich position (C3).