The coordination chemistry of enantiopure diimines derived from 1-phosphanorbornadiene-2-carboxaldehydes

The reaction of trans -1,2-diaminocyclohexane with enantiopure (R )-2-formyl-1-phosphanorbornadiene (1) takes place with efficient kinetic resolution and gives an easily separable mixture of the corresponding (S ,S )-bis-imine (3) and (R )-mono-imine (4). The absolute configuration of 3 has been established by X-ray crystal structure analysis. The coordination chemistry of enantiopure 3 with Pd(II), Rh(I), and Ru(II) has been investigated. The reaction of [PdCl2(cod)] mainly affords a binuclear complex 6 whose structure has been established by X-ray analysis. One View the MathML sourcePdCl3- unit is coordinated to one P and one PdCl+ unit is tricoordinated to the other P and the two N. The two square planar units are parallel and the Pd⋯Pd distance is 3.1787(5) Å. The reaction of [RhCl(cod)]2 gives the very reactive tetracoordinate cationic [Rh(P2N2)]+ species 7 which is able to activate one C–Cl bond of chloroform to give the dichloromethyl-Rh complex (8) whose octahedral structure has been ascertained by X-ray analysis.