| Autor: |
Chase DT; Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA., Moerdyk JP, Bielawski CW |
| Jazyk: |
angličtina |
| Zdroj: |
Organic letters [Org Lett] 2012 Nov 02; Vol. 14 (21), pp. 5510-3. Date of Electronic Publication: 2012 Oct 24. |
| DOI: |
10.1021/ol302596r |
| Abstrakt: |
The reversible [2 + 1] cycloadditions between an N,N'-diamidocarbene (DAC) and eight aldehydes were examined using NMR spectroscopy. Variable temperature magnetization transfer experiments revealed higher exchange rates and lower activation barriers when electron-deficient aldehydes were employed. Likewise, competitive equilibrium studies indicated a thermodynamic preference for electron-deficient aryl and sterically unhindered alkyl aldehydes compared to more electron-rich or bulkier substrates. Collectively, these and other data collected were consistent with the oxiranation process proceeding in an asynchronous manner. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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