N-substituted aminobiphenyl palladacycles stabilized by dialkylterphenyl phosphanes: Preparation and applications in C N cross-coupling reactions

Neutral and cationic N-methyl- N-phenyl-2-aminobiphenyl methanesulfonate palladacycles stabilized with dialkylterphenyl phosphanes have been prepared characterized. structures are favored the less bulky phosphane PMe2ArXyl2, L1, while more sterically demanding ligands PiPr2ArXyl2, L3, PCyp2ArXyl2 (Cyp = cyclopentyl), L4, lead to complexes in which exhibits a bidentate ?1-P, ?1-Carene coordination mode involving one of ipso carbon atoms flanking terphenyl aryl ring. The were evaluated for activity CN cross-coupling reactions [Pd(N-methyl-2-aminobiphenyl)L4](OMs) (OMs mesylate) was identified as most efficient precatalyst, facilitating coupling chlorides secondary primary amines indoles.