ISSN:
0018-019X
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The catalytic hydrogenation in acidic solution (pH ∼ 2) of the title compoundIn order to represent this and the related compounds by meaningful abbreviations, we shall adopt the numerotation system proposed in the literature [8] [12]. The complete abbreviation of the title compound is [Ni(5, 7, 7, 12, 14, 14-Me6-[14]-4, 11-diene-1, 4, 8, 11-N4)]2+. As in the present work the 14-membered ring system with six methyl groups remains unchanged, we shall use [Ni(4, 11-dieneN4)]2+ and [Ni(4, 11-aneN4)]2+ and [Ni(4, 11-aneN4)]2+ for the complex with the unsaturated and saturated ligand, respectively. [Ni(4, 11-dieneN4)]2+ (I) has been studied. The reaction yields only C-meso- 5, 7, 7, 12, 14, 14-hexa-methyl-1, 4, 8, 11-tetraaza-cyclotetradecane-nickel (II) (C-meso-[Ni(4, 11-aneN4)]2+), when meso-[Ni(4, 11-dieneN4)]2+ is the starting material. Rac-[Ni(4, 11-dieneN4)]2+ yields the unstable α-C-rac-[Ni(4, 11-aneN4)]2+. When optically active [Ni(4, 11-dieneN4)]2+ is reduced, optically active α-[Ni(4, 11-aneN4)]2+ is obtained, which in neutral or basic solution shows mutarotation due to conversion into optically active β-[Ni(4, 11-aneN4)]2+ no racemization is observed. Reaction with cyanide ions yields the optically active free tetramine ligand.The reaction mechanism of this asymmetric synthesis is discussed.
Zusätzliches Material:
2 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hlca.19740570118
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