title: Pd-PEPPSI-IPentCl: A Useful Catalyst for the Coupling of 2-Aminopyridine Derivatives.
abstract: The Pd-PEPPSI-IPentClprecatalyst (PEPPSI=pyridine-enhanced precatalyst preparation stabilisation initiation) has been demonstrated to be highly effective in the coupling of hetero(aryl)chlorides to free 2-aminopyridine substrates to produce N-(hetero)aryl-2-aminopyridine derivatives. The catalyst has proven to be competent in a number of other difficult cross-coupling reactions owing to the combination of the 3-pentyl-substituted N-aryl groups and the chlorines on the backbone of the N-heterocyclic carbene (NHC) core. This same reactivity here allows couplings to take place under very mild conditions (e.g., NaBHT (BHT=2,6-di-tert-butyl-4-methylphenol) or carbonate base) such that sensitive functional groups including esters, ketones and nitriles are tolerated. Key is that the same bulk that drives the cross-coupling also mitigates poisoning of the Pd centre with the 2-aminopyridine functionality in the starting materials and/or products, which forces the catalyst into inactive, stable resting states.
authors.affiliation: Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada.
authors.forename: Abir
authors.initials: A
authors.lastname: Khadra
authors.affiliation: BioParc, 850 Bld Sébastien Brant, 67400, Illkirch, France.
authors.forename: Stanislas
authors.initials: S
authors.lastname: Mayer
authors.affiliation: Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada.|Director, Centre for Catalysis Research and Innovation (CCRI) and, Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, K1N6N5, Canada.
authors.forename: Michael G
authors.identifier: http://orcid.org/0000-0002-4625-5696
authors.initials: MG
authors.lastname: Organ
keywords: 2-aminopyridine; PEPPSI; amination; cross-coupling; palladium