Carbohydrate-metallocene conjugates: selective formation of a zirconadioxacyclopentane-type dimer from the reaction of a bis(enolate)ZrCp2 reagent with a glucofuranoside derivative.
The zirconocene enolate complex bis(2-propenolato)ZrCp2 (1) reacts with two molar equivalents of the 1,2,3,4-O-tetramethyl-alpha-D-glucopyranoside (2) with liberation of two equivalents of acetone to yield cleanly the bis(carbohydrate)zirconcene complex (3). Alternatively 1 and the "bifunctional" glucose derivative 3-O-benzyl-1,2-O-isopropylidene-glucofuranoside (4) react to the corresponding zirconadioxacyclopentane-type metallacyclic product that was isolated as the respective dimer (5) featuring a sequence of linearly anellated five-, four-, five-membered metallacycles. Both carbohydrate zirconocene complexes 3 and 5 were characterized by NMR experiments as well as by X-ray diffraction.
Meyer zu Berstenhorst
Birgit
B
Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, 48149 Münster, Germany.
Erker
Gerhard
G
Kehr
Gerald
G
Fröhlich
Roland
R
D002236:Carbohydrate Conformation; D002241:Carbohydrates / Q000737:chemistry*; D015392:Chemistry, Inorganic / Q000379:methods*; D018360:Crystallography, X-Ray; D019281:Dimerization; D005663:Furans / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction; D015040:Zirconium / Q000737:chemistry*
D002241:Carbohydrates; D005663:Furans; D009942:Organometallic Compounds; C013108:metallocene; D015040:Zirconium; D005947:Glucose