New Pd(II) and Pt(II)-diaminophosphine complexes bearing cyclohexyl or isopropyl moiety: use of Pd(II) complexes as precatalyst in Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions

Two new diaminophosphine ligands, N,N'-bis(dicyclohexylphosphino)-2-(aminomethyl)aniline (1) and N,N'-bis(diisopropylphosphino)-2-(aminomethyl)aniline (2) were synthesized by the reaction of 2-(aminomethyl)aniline with two equivalents of Cy2PCl or (iPr)(2)PCl, respectively. The reactions of 1 and 2 with MCl2 (cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) yield complexes [cis-Pd(L2PNHC6H4CH2NHPL2)Cl-2] (L = Cy 3, iPr 4) and [cisPt(L2PNHC6H4CH2NHPL2)Cl-2] (L = Cy 5, iPr 6), respectively. The catalytic activity of the palladium complexes was investigated in the Suzuki-Miyaura cross-coupling reaction in the presence of Cs2CO3 as a base. The palladium complexes were also found to be highly active catalysts in the Mizoroki Heck reaction.