58620-26-1Relevant academic research and scientific papers
Catalytic transformations of alkylthiophenes
Mashkina,Chernov
, p. 209 - 215 (2007/10/03)
The transformations of alkylthiophenes in the presence of amorphous aluminosilicate and decationated zeolite HNaY were studied. Substituted thiophenes with R = 2- and 3-Me, 2-Et, and 2-iso-Pr undergo dealkylation to thiophene with close rates, migration of the alkyl group from the 9α- to the β-position of the thiophene ring (or in the opposite direction with an elevated rate), and decomposition with H2S elimination. The dealkylation rate of 2-substituted thiophenes with a branched-chain radical (R = iso-Pr, terf-Bu) is much higher and the elimination rate with this radical is lower than those for normal-chain radicals; the isomerization step is virtually absent. Di-, tri-, and tetrasubstituted thiophenes with R = Et and iso-Pr undergo stepwise dealkylation, which is facilitated by an increase in the degree of substitution on the thiophene ring. Thiophene and its lower homologues can be obtained by the transformation of a mixture of high-molecular thiophenes. Copyright
STABLE HETEROARENIUM IONS-IX. DISPROPORTIONATION OF ALKYLTHIOPHENIUM IONS AND ITS USE FOR THE SYNTHESIS OF 2,4-DIALKYLTHIOPHENES
Belen'kii, L. I.,Yakubov, A. P.
, p. 759 - 762 (2007/10/02)
A number of isopropyl and ethyl substituted thiophenium ions has been generated by the alkylation of thiophene and protonation of alkylthiophenes.Disproportionation of these ions has been studied at room temperature and at the b.p. of 1,2-dichloroethane used as a solvent while preparing the ions. 2,4-Diethylthiophene has been prepared from its mixture with the 2,5-isomer by disproportionation of the 2,5-diethyl-2H-thiophenium ion.
