Formation and reactivity of 1-pyrrolyl-2,2,2-trifluoroethyl cations
- 1 October 1990
- journal article
- Published by Canadian Science Publishing in Canadian Journal of Chemistry
- Vol. 68 (10) , 1709-1713
- https://doi.org/10.1139/v90-265
Abstract
1-(1-Methyl-2-pyrrolyl)-2,2,2-trifluoroethyl p-nitrobenzoate (3) reacts by carbocation formation with an m value for the dependence of rate on the solvent polarity parameter YOTs of 0.56, and a rate 41 times slower than (1-methyl-2-pyrrolyl)methyl p-nitrobenzoate. The products from 3 include significant amounts of material derived from solvent attack at the 5-position of the pyrrole ring. The results indicate a high degree of charge delocalization by the strongly donating pyrrolyl group, resulting in a low k(H)/k(CF3) rate ratio and nucleophilic attack on the ring. 1,1, l-Trifluoro-2-(1-methyl-2-pyrrolyl)propan-2-ol (10) reacted with CF3CO2H via a tertiary carbocation, which led to dimeric products resulting from electrophilic substitution on the pyrrole ring. Keywords: pyrrole, trifluoromethyl substituents, carbocations.Keywords
This publication has 0 references indexed in Scilit: