Syntheses and Structures of Sterically Congested Linear and Branched Cobalta[n]triangulanes
| Autor: | Sergei I. Kozhushkov, Jan Foerstner, Li Yong, Rudolf Wartchow, Dirk Stellfeldt, Holger Butenschön, Alf Kakoschke, Armin de Meijere |
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| Rok vydání: | 2006 |
| Předmět: |
Steric effects
010405 organic chemistry Chemistry Stereochemistry Ligand Organic Chemistry chemistry.chemical_element General Chemistry 010402 general chemistry Methylenecyclopropane 01 natural sciences Sodium amalgam Medicinal chemistry Catalysis 0104 chemical sciences chemistry.chemical_compound Cyclopentadienyl complex Yield (chemistry) Thermal stability Cobalt |
| Zdroj: | Chemistry - A European Journal. 12:5642-5647 |
| ISSN: | 1521-3765 0947-6539 |
| Popis: | Treatment of {eta(5):eta(1)[2-(di-tert-butylphosphanyl-P)ethyl]cyclopentadienyl}cobalt(I) chloride (5) with methylenecyclopropane (3) or bicyclopropylidene (4), as well as with their spirocyclopropanated analogues methylenespiropentane (7), cyclopropylidenespiropentane (10), or 7,7'-bi(dispiro[2.0.2.1]heptylidene) (15) in the presence of sodium amalgam at -50 degrees C, furnished the stable cobalt complexes 6, 9, 8, 11, and 16, respectively, in 72, 83, 84, 86, and 54 % isolated yield, respectively. The complexes 14 and 16 were also obtained by ligand exchange of the ethene complex {eta(5):eta(1)[2-(di-tert-butylphosphanyl-P)ethyl]cyclopentadienyl}(eta(2)-ethene)cobalt(I) (12) with 13 and 15 in 79 and 52 % yield, respectively. The X-ray crystal-structure analyses of complexes 9, 14, and 16, as well as the NMR-spectroscopic data of all complexes, reveal that they can be regarded as linear and branched cobalta[n]triangulanes. The thermal stability of complexes 6, 8, and 9 up to 109, 145, and 160 degrees C was determined by differential thermal analysis-thermogravimetry (DTA-TG) analysis. |
| Databáze: | OpenAIRE |
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