- Pd-catalyzed aryl amination mediated by well defined, N-heterocyclic carbene (NHC)-Pd precatalysts, PEPPSI.
Pd-catalyzed aryl amination mediated by well defined, N-heterocyclic carbene (NHC)-Pd precatalysts, PEPPSI.
Chemistry (Weinheim an der Bergstrasse, Germany) (2008-01-29)
Michael G Organ, Mirvat Abdel-Hadi, Stephanie Avola, Igor Dubovyk, Niloufar Hadei, Eric Assen B Kantchev, Christopher J O'Brien, Mahmoud Sayah, Cory Valente
PMID18224651
摘要
Pd-N-heterocyclic carbene (NHC)-catalyzed Buchwald-Hartwig amination protocols mediated by Pd-PEPPSI precatalysts is described. These protocols provide access to a range of hindered and functionalized drug-like aryl amines in high yield with both electron-deficient and electron-rich aryl- and heteroaryl chlorides and bromides. Variations in solvent polarity, base and temperature are tolerated, enhancing the scope and utility of this protocol. A mechanistic rationalization for base strength (pKb) requirements is also provided.