here a palladium(II)-catalyzed oxidative cyclization reaction of N-allylimines derived from methyl ketones, typically acetophenones, affording pyrrole derivatives at room temperature under oxygen atmosphere. The reaction likely proceeds through α-palladation of the imine followed by olefin migratory insertion and β-hydride elimination, thus representing a new example of aerobicdehydrogenative Heck cyclization
Aerobic Synthesis of Pyrroles and Dihydropyrroles from Imines: Palladium(II)-Catalyzed Intramolecular CH Dehydrogenative Cyclization
作者:Zhuangzhi Shi、Mamta Suri、Frank Glorius
DOI:10.1002/anie.201300477
日期:2013.4.26
sp3ectacularly mild! An efficient PdII‐catalyzed intramoleculardehydrogenativecyclization of imines affords (dihydro)pyrrole products using molecular oxygen as the sole oxidant. This mild formal sp3‐CH functionalization allows rapid and atom‐economical assembly of (dihydro)pyrrole rings from inexpensive and readily available allylamines and ketones. A broad range of functional groups are tolerated