| Autor: |
Tanaka Y; Laboratory of Molecular Transformation, Graduate School of Pharmaceutical Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan. tanaka@mail.pharm.tohoku.ac.jp, Arakawa M, Yamaguchi Y, Hori C, Ueno M, Tanaka T, Imahori T, Kondo Y |
| Jazyk: |
angličtina |
| Zdroj: |
Chemistry, an Asian journal [Chem Asian J] 2006 Oct 20; Vol. 1 (4), pp. 581-5. |
| DOI: |
10.1002/asia.200600099 |
| Abstrakt: |
A metal-free acetylide was observed by using NMR spectroscopy. Metal-free acetylides are closely related to reactive intermediates (carbanions) in solution; therefore, they have been regarded as unobservable species. However, we generated this highly reactive and unstable species through the deprotonation of phenylacetylene by using the strong nonmetallic phosphazene base tBu-P4. In the presence of tBu-P4, the J coupling between the ethynyl carbon and hydrogen nuclei (1J(C,H)) of phenylacetylene disappeared; this indicates the deprotonation of the alkyne terminal. Furthermore, a large low-field shift (approximately 90 ppm) of the alkyne carbon resonance was observed. We concluded that we have observed a metal-free carbanion with a formal charge on an sp-hybridized carbon atom for the first time. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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