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

Abstract

The reactions of an S-bridged trinuclear palladium(II) complex, [Pd₃(D-pen-N,O,S)₃] (D-H₂pen = 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_RR) and [Pd(D-pen-N,S)(S,S-chxn)] (2_SSS), possible for 2, 2_SSS was exclusively isolated in a high yield.