Conversion of d-penicillaminato trinuclear to mononuclear palladium(ii) structure by diamine ligands: remarkable enantioselectivity toward racemic 1,2-cyclohexanediamine

The reactions of an S-bridged trinuclear palladium(ii) complex, Pd(3)(d-pen-N,O,S)(3)] (d-H(2)pen = d-penicillamine), with ethylenediamine (en) and racemic (R,R/S,S) 1,2-cyclohexanediamine (chxn) in water gave mononuclear palladium(ii) complexes, Pd(d-pen-N,S)(en)] (1) and Pd(d-pen-N,S)(chxn)] (2), respectively. Of two diastereomers, Pd(d-pen-N,S)(R,R-chxn)] (2(R)) and Pd(d-pen-N,S)(S,S-chxn)] (2(S)), possible for 2, 2(S) was exclusively isolated in a high yield.