Studies of the Metal Complexes of Cyclohexane Derivatives. VIII. Preparation and Properties of Platinum(II) and Cobalt(III) Complexes Containing (1R,2S,3S)- or (1S,2R,3R)-3-methyl-1,2-cyclohexanediamine

Article abstract of DOI:10.1246/bcsj.57.3430

(1RS,2SR,3SR)-3-Methyl-1,2-cyclohexanediamine (3m-chxn), a methyl derivative of cis-1,2-cyclohexanediamine, was prepared and optically resolved.The absolute configurations of the enantiomers obtained were assigned on the basis of the Cotton effect of the trans-dichlorobis(diamine) complexes, each containing active 3m-chxn.The complexes of the 3)₂L>²⁺, ²⁺, and 3>³⁺ types (en=1,2-ethanediamine, L=R,S,S- or S,R,R-3m-chxn) were also synthesized and characterized on the basis of their absorption, CD, and ¹³C NMR spectra.It has been found that the chelate rings adopted by R,S,S- and S,R,R-3m-chxn predominantly take δ and λ conformations respectively, because of the preferred equatorial orientation of the C₂-C₃ bond of the cyclohexane ring.The four diastereomers of 3>³⁺ were chromatographically isolated and assigned to fac-Λ(lel₃), mer-Λ(lel₃), fac-Δ(ob₃), and mer-Δ(ob₃).