Stereochemical investigation of a kinetically labile chiral organopalladium complex in solution

According to the relative locations of the R and S stereogenic centres in t he diamine chelate, the kinetically labile complex (+)-[Pd{(S)-CH3CH(1-C10H 6)NMe2-C-2,N} {(R,S)-Me2NCH(Me)CH(Me)NMe2-N,N'}]ClO4 exists as an equilibri um mixture of two stereochemically distinct isomers in solution. The equili brium ratio is temperature and solvent dependent. In d(2)-dichloromethane, the minor isomer observed at room temperature diminishes when the temperatu re is lowered to -20 degrees C. A low temperature 2-D ROESY NMR experiment is used to identify the sterically favored major isomer in solution and hen ce to evaluate the efficiency of the chiral inductive effects of coordinate d (S)dimethyl(1-(alpha-naphthyl)ethyl)amine. (C) 1999 Elsevier Science S.A. All rights reserved.