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Synthesis of the cobalt–alkyne complex (η5-C5H5)(PPh3)Co{η2-(Me3Si)CC(CO2Et)} and structural characterization of trimethylsilyl substituted cobaltacyclopentadiene complexes derived therefrom
- Source :
- Journal of Organometallic Chemistry. 749:100-105
- Publication Year :
- 2014
- Publisher :
- Elsevier BV, 2014.
-
Abstract
- The reaction of (η5-C5H5)Co(PPh 3)2 with TMSCC(CO2Et) leads to the formation of the cobalt-alkyne complex (η5-C5H5) (PPh3)Co{η2-(Me3Si)CC(CO2Et)} (6). In benzene-d6 solution containing PPh3, 6 undergoes slow conversion to the cobaltacyclopentadiene complex (η5-C 5H5)(PPh3)Co{κ2-(TMS) CC(CO2Et)C(TMS)C(CO2Et)} (7, TMS = SiMe3). Alternatively, reaction of 6 and PhCCPh forms the metallacyclopentadiene regioisomers (η5-C5H5)(PPh 3)Co{κ2-(R1)CC(R2)C(Ph) =C(Ph)} [9-major, R1 = SiMe3, R2 = CO2Et; 9-minor, R1 = CO2Et, R2 = SiMe3). The metallacycle substitution pattern in 9-major and 9-minor is readily deduced from the 1H NMR spectral resonances of the diastereotopic ethoxycarbonyl hydrogens. When the diastereotopic hydrogens of the ethoxycarbonyl have similar chemical shifts the ester is situated on the β-carbon of the metallacycle. When the methylene hydrogens give rise to well-separated resonances the ethoxycarbonyl is situated on the α-carbon of the metallacycle. The solid state structures of 7 and 9-major were determined by X-ray crystallography. © 2013 Elsevier B.V. All rights reserved.
- Subjects :
- chemistry.chemical_classification
Trimethylsilyl
Stereochemistry
Chemical shift
Organic Chemistry
Metallacyclopentadiene
Cobaltacycle
chemistry.chemical_element
Alkyne
Trimethylsilyl alkyne
Cobaltacyclopentadiene
Metallacycle
Biochemistry
Medicinal chemistry
Inorganic Chemistry
chemistry.chemical_compound
chemistry
Materials Chemistry
Structural isomer
Proton NMR
Cobalt-alkyne
Physical and Theoretical Chemistry
Methylene
Other Chemical Sciences
Cobalt
Subjects
Details
- ISSN :
- 0022328X
- Volume :
- 749
- Database :
- OpenAIRE
- Journal :
- Journal of Organometallic Chemistry
- Accession number :
- edsair.doi.dedup.....1a235aef808bf85dfbf3d60e96b46bf3