A PCN Ligand System. Exclusive C−C Activation with Rhodium(I) and C−H Activation with Platinum(II)

Abstract

Reaction of the new aromatic aminophosphine ligand 1-((diethylamino)methyl)-3-((di-tert-butylphosphino)methyl)-2,4,6-trimethylbenzene (4) with [Rh(COE)2Cl]2 (COE = cyclooctene) or with [Rh(ethylene)2Cl]2 at room temperature results in selective carbon−carbon bond activation, yielding the complex ClRh(CH3)[C6H(CH3)2(CH2N(C2H5)2)(CH2P(t-Bu)2)] (5). No competing C−H activation was observed during the course of the reaction. When 4 was reacted with (COD)PtCl2 (COD = cyclooctadiene), selective C−H activation of the methyl group situated between the phosphine and amine groups took place, with concomitant intramolecular H transfer to the amine ligand, resulting in the zwitterionic Pt(II) complex Cl2PtCH2(C6H(CH3)2(CH2NH(C2H5)2)(CH2P(t-Bu)2) (11).