Application of indole-based monophosphine in ppm level Pd-catalyzed C–N bond formation

Abstract

A new indolyphosphine ligand bearing multi-electron-donating methoxy groups has been designed for Pd-catalyzed Buchwald-Hartwig amination. It is worth noting that this new catalyst system was found to be highly effective in facilitating the cross-coupling reaction even at parts per million levels of palladium catalyst. A wide range of aryl chlorides as well as amine nucleophiles were successfully employed for the aromatic C–N bond-forming reaction. Remarkably, the extremely steric congested amine (i.e. 2,6-diisopropylaniline) was also coupled well with aryl chloride under the newly developed catalyst system.