(−)-Sparteine copper(II) diacetate

Abstract

The chiral nitrogen‐chelating alkaloid (−)‐sparteine acts as a bidentate ligand, reacting with copper(II) acetate in ethanol to form the title complex, [Cu(CH3COO)2(C15H26N2)], with the two acetate groups occupying the remaining coordination sites in a monodentate fashion to produce a distorted four‐coordinate tetrahedral structure. The dihedral angle between the N—Cu—N and O—Cu—O planes is 45.8 (3)°.

Unexpected structural similarity between the chlorocopper(i) unit and the methyllithium and phenyllithium units. First complexes between (−)-sparteine and copper(i) chloride: synthesis and structural characterisation

“…Structural information on copper (À)-sparteine complexes appears at present to be limited to dichloro{(À)-sparteine}copper(II) 3 and {(À)-sparteine}copper(II) diacetate. 4 Owing to our ongoing interest in complexes between copper(I) and hard-donor ligands 5 and, moreover, in the use of various metal complexes containing chiral ligands for organic synthetic applications, 6,7 we embarked on an investigation of those complexes formed in a direct reaction between copper(I) chloride and (À)-sparteine.…”

Mass Spectrometry of Metal Complexes of Bis-Quinolizidine Alkaloids: Electron Ionization and Fast Atom Bombardment Mass Spectral Study of Copper(II) (–)-Sparteine and (–)-α-Isosparteine Complexes

“…the formation of complexes with transition metal(II) leads to a conversion of the nitrogen atom configuration in the sparteine ligand: as a consequence, all four alkaloid rings adopt the chair configuration and the configuration at the A/B and c/D ring junctions are trans and cis, respectively. [19][20][21][22][23][24]26,27 this conformation differs from that of the free (-)-sparteine ligand. 32,33 on the other hand, it has been reported that (-)-a-isosparteine remains structurally unchanged upon complexation 25,28 (figure 2).…”

“…considerable effort has been devoted to the study of these compounds by infrared and nuclear magnetic resonance spectroscopy, as well as by X-ray methods. [18][19][20][21]23,24,[26][27][28][41][42][43][44][45] However, the EI and fAB fragmentations of these compounds have not been reported.…”

“…the goal of this study was to establish if is its possible to differentiate transition metal(II) of zinc(II) and copper(II) dichloride (dibromide, diacetate) complexes of (-)-sparteine and (-)-a-isosparteine from their EI and fAB mass spectra. 1,[18][19][20][21]23,24 this problem has not been discussed previously in the literature.…”

Electron ionization and fast atom bombardment mass spectral study for differentiation of ligand of zinc(II) (–)‐sparteine and (–)‐α‐isosparteine complexes

“…20,21 The formation of complexes leads to a conversion of the nitrogen atom configuration in the sparteine ligand; as a consequence, all four alkaloid rings adopt the chair conformation, and the configurations at the A/B and C/D ring junctions are trans and cis, respectively. 15,[22][23][24] This conformation differs from that of the free (-)-sparteine ligand, in which the C ring takes the boat form, and the configuration at the C/D ring junction is trans.…”