The gear effect. VII—Conformational analysis of methyl N,N-diisopropylcarbamate, its thiol and diseleno analogues. An experimental proof for a two-step conformational interconversion mechanism
✍ Scribed by Tommy Liljefors; Jan Sandström
- Publisher
- John Wiley and Sons
- Year
- 1977
- Tongue
- English
- Weight
- 461 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
The conformations of the isopropyl groups and the barriers to conformational interconversion in methyl N,N‐diisopropylcarbamate, its thiol and seleno analogues have been studied by ^1^H d.n.m.r. In the diselenocarbamate, complete bandshape analysis of the Se‐methyl proton signals proves unequivocally that the conformational interconversion takes place by rotation of one isopropyl group at a time rather than by a concerted rotation of both groups. The populations and barriers observed for the new compounds fit well into the general scheme found previously for other N,N‐diisopropylamides and ‐thioamides.