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 Cy 2 PCl or (iPr) 2 PCl, respectively. The reactions of 1 and 2 with MCl 2 (cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) yield complexes [ cis -Pd(L 2 P NHC 6 H 4 CH 2 NH P L 2 )Cl 2 ] (L = Cy 3 , iPr 4 ) and [ cis - Pt(L 2 P NHC 6 H 4 CH 2 NH P L 2 )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 Cs 2 CO 3 as a base. The palladium complexes were also found to be highly active catalysts in the Mizoroki{Heck reaction.