Binuclear copper(II) complexes of 5-N-(beta-ketoen)amino-5-deoxy-1,2-O-isopropylidene-alpha-D-glucofuranoses: synthesis, structure, and catecholoxidase activity.
The synthesis of 5-amino-5-deoxy-1,2-O-isopropylidene-alpha-D-glucofuranose (8) was carried out via 5-azido-5-deoxy-1,2:3,4-O-diisopropylidene-alpha-D-glucofuranose (6), its reduction with Raney-Nickel and deprotection. 5-N-(beta-Ketoen)amino-5-deoxy-1,2-O-isopropylidene-alpha-D-glucofuranoses (8a-f) were synthesized from 5-amino-5-deoxy-1,2-O-isopropylidene-alpha-D-glucofuranose and beta-ketoenolethers leading to ligands with symmetrically substituted double bonds (8a, 8b) and e/z isomeric mixtures with unsymmetrical substitution (8c-f). Reaction of the ligands with Cu(II) ions leads to binuclear complexes of the general formula Cu2L2. In contrast to copper(II) complexes which are not derived from amino carbohydrates the metal centers in the compounds saturate their coordination sphere by complexation of additional solvent molecules, interaction with neighboring complex molecules, or free hydroxyl groups of the own ligand. Residues of the ketoen moiety, R1 and R2, also influence the electronic properties of the metal centers. The combination of factors leads to different catalytic properties of the complexes in catecholoxidase-like reactions.
Gottschaldt
Michael
M
Friedrich Schiller University Jena, Institute of Organic and Macromolecular Chemistry, Humboldtstrasse 10, 07743 Jena, Germany. michael.gottschaldt@uni-jena.de
Wegner
Rainer
R
Görls
Helmar
H
Klüfers
Peter
P
Jäger
Ernst-G
EG
Klemm
Dieter
D
D004156:Catechol Oxidase / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004789:Enzyme Activation; D004987:Ethers / Q000737:chemistry; D005947:Glucose / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
D004987:Ethers; D008024:Ligands; D009942:Organometallic Compounds; D003300:Copper; D004156:Catechol Oxidase; D005947:Glucose