An Examination of the Palladium/Mor-DalPhos Catalyst System in the Context of Selective Ammonia Monoarylation at Room Temperature

作者：Alsabeh Pamela G; Lundgren Rylan J; McDonald Robert; Seechurn Carin C C Johansson; Colacot Thomas J; Stradiotto Mark^*

来源：Chemistry - A European Journal, 2013, 19(6): 2131-2141.

DOI：10.1002/chem.201203640

• amination
• anilines
• N
• P ligands
• palladium
• precatalysts

An examination of the [{Pd(cinnamyl)Cl}2]/Mor-DalPhos (Mor-DalPhos=di(1-adamantyl)-2-morpholinophenylphosphine) catalyst system in BuchwaldHartwig aminations employing ammonia was conducted to better understand the catalyst formation process and to guide the development of precatalysts for otherwise challenging room-temperature ammonia monoarylations. The combination of [{Pd(cinnamyl)Cl}2] and Mor-DalPhos afforded [(2-P,N-Mor-DalPhos)Pd(1-cinnamyl)Cl] (2), which, in the presence of a base and chlorobenzene, generated [(2-P,N-Mor-DalPhos)Pd(Ph)Cl] (1a). Halide abstraction from 1a afforded [(3-P,N,O-Mor-DalPhos)Pd(Ph)]OTf (5), bringing to light a potential stabilizing interaction that is offered by Mor-DalPhos. An examination of [(2-P,N-Mor-DalPhos)Pd(aryl)Cl] (1bf) and related precatalysts for the coupling of ammonia and chlorobenzene at room temperature established the suitability of 1a in such challenging applications. The scope of reactivity for the use of 1a (5mol%) encompassed a range of (hetero)aryl (pseudo)halides (X=Cl, Br, I, OTs) with diverse substituents (alkyl, aryl, ether, thioether, ketone, amine, fluoro, trifluoromethyl, and nitrile), including chemoselective arylations.

• 出版日期2013-2