Chloride-ion promoted dehydrochlorination of 1,1-diaryl-2,2,2-trichloroethanes in dipolar aprotic solvents
- 1 January 1972
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 2
- No. 15,p. 2308-2314
- https://doi.org/10.1039/p29720002308
Abstract
Rate constants are reported for the second-order dehydrochlorination reactions of Ar2CH·CCl3 compounds promoted by Bun 4NCl in acetone and by LiCl in dimethylformamide. Rate data for the dehydrochlorination reactions of Ar(Ph)CH·CCl3 compounds in the latter system are also presented. A modified Hammett-equation analysis yields ρ values of 1·31 (acetone) and 0·99 (dimethylformamide). It is considered that these parameters are diagnostic of a significant degree of β-carbanionic character in the E2 transition states, and that the system provides the first clear example of a halide-promoted E2H reaction. The E2C mechanism can be definitely rejected for this particular case.Keywords
This publication has 0 references indexed in Scilit: