Abstract
Sigmatropic [1,3] B shift was observed by 2D 1H EXSY NMR experiments in diethyl(1-indenyl)borane 1i prepared in 83% yield from indenyl lithium and chlorodiethylborane. The activation barrier of the rearrangement (EA = 17.7±0.2 kcal mol-1, lnA = 28.6±0.5) was determined from a series of 2D 1H EXSY spectra recorded in the temperature interval 25-80°C. After prolonged storage at ambient temperatures or short heating at 100°C an equilibrium between 1i, diethyl(3-indenyl)borane 4i, and diethyl(2-indenyl)borane 5i is established (the equilibrium ratio 1i:4i:5i is 1:2.3:0.2). Addition of an excess of pentadeuteropyridiine leads to a new equilibrium between corresponding complexes (the ratio 1j:4j:5j is 1:3.2:0.2).
Original language | English |
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Pages (from-to) | 271-277 |
Number of pages | 7 |
Journal | Main Group Metal Chemistry |
Volume | 21 |
Issue number | 5 |
DOIs | |
Publication status | Published - 1998 Jan 1 |
Externally published | Yes |
ASJC Scopus subject areas
- Chemistry(all)
- Condensed Matter Physics
- Metals and Alloys
- Materials Chemistry