title: Trineopentylphosphine: a conformationally flexible ligand for the coupling of sterically demanding substrates in the Buchwald-Hartwig amination and Suzuki-Miyaura reaction.
abstract: Trineopentylphosphine (TNpP) in combination with palladium provides a highly effective catalyst for the Buchwald-Hartwig coupling of sterically demanding aryl bromides and chlorides with sterically hindered aniline derivatives. Excellent yields are obtained even when both substrates include 2,6-diisopropyl substituents. Notably, the reaction rate is inversely related to the steric demand of the substrates. X-ray crystallographic structures of Pd(TNpP)2, [Pd(4-t-Bu-C6H4)(TNpP)(μ-Br)]2, and [Pd(2-Me-C6H4)(TNpP)(μ-Br)]2 are reported. These structures suggest that the conformational flexibility of the TNpP ligand plays a key role in allowing the catalyst to couple hindered substrates. The Pd/TNpP system also shows good activity for the Suzuki coupling of hindered aryl bromides.
authors: Department of Chemistry, The University of Alabama, Box 870336, Tuscaloosa, Alabama 35487-0336, USA.
authors: Steven M
authors: SM
authors: Raders
authors: Jane N
authors: JN
authors: Moore
authors: Jacquelynn K
authors: JK
authors: Parks
authors: Ashley D
authors: AD
authors: Miller
authors: Thomas M
authors: TM
authors: Leißing
authors: Steven P
authors: SP
authors: Kelley
authors: Robin D
authors: RD
authors: Rogers
authors: Kevin H
authors: KH
authors: Shaughnessy
mesh_terms: D000586:Amination; D000814:Aniline Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry; D010720:Phosphines / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D008024:Ligands; D009942:Organometallic Compounds; D010720:Phosphines; D010165:Palladium; C023650:aniline