Theoretical studies on the elimination of hydrogen fluoride from alkyl fluoride and its substituent effect
✍ Scribed by Xiao-Yuan Fu; Qing-Ming Li; De-Cai Fang
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 288 KB
- Volume
- 57
- Category
- Article
- ISSN
- 0020-7608
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✦ Synopsis
The reaction mechanism of the a, a and a, /3 elimination of hydrogen fluorides from alkyl fluorides has been studied theoretically. For fluoroethane as a reactant, the transition state (1s) optimized at the level of the 6-31~** basis set shows that the Q, /3 elimination proceeds via a four membered-ring TS with a barrier height 64.6 kcal/mol, while the a, a elimination, via a three-membered ring TS with a 83.7 kcal/mol barrier. Four substituents, CH,, CN, F, and NH,, were used to investigate the substituent effect of elimination by using the 3-21c basis set. The calculated barriers show that NH,-substituted alkyl fluorides favor both the a, Q and a, @ elimination and these two reactions would be expected to proceed simultaneously. 0 19% John WiIey & Sons, Inc. carbene and hydrogen halide (X represents the The pyrolysis of alkyl halides in the vapor phase has been extensively studied by experimentalists [ 1-51. However, there are very limited theoretical studies [6, 71 on these interesting chemical reactions. In this article, our aim was to study the