en
Scientific article
English

The Synthesis and Protonation of 1,1-Di(1-pyrrolyl)alkenes

Published inHelvetica chimica acta, vol. 68, no. 8, p. 2282-2286
Publication date1985-12-18
First online date2004-10-25
Abstract

It is shown that lithiation of di(1-pyrrolyl)methane (3) can be directed either towards the C(α) ring positions or to the central CH₂ group, depending upon the solvent and the complexing agents chosen. Di(1-pyrrolyl)-methyllithium (6), resulting from CH₂ deprotonation, is intercepted by aldehydes and converted to the title alkenes in a few straightforward steps. Protonation of 1,1-di(1-pyrrolyl)ethylene (10) is found to occur under kinetic control at the terminal olefinic position. In HBF₄. Me₂O the resulting 5-azionafulvene-type ion 14 can be observed by low-temperature NMR spectroscopy. In FSO₃H, however, protonation is directed under thermodynamic control to both pyrrole rings. The resulting symmetrical dication 13 persists even at room temperature.

eng
Citation (ISO format)
SCHÄRER, Jean-Claude, ETIENNE, Robert, BURGER, Ulrich. The Synthesis and Protonation of 1,1-Di(1-pyrrolyl)alkenes. In: Helvetica chimica acta, 1985, vol. 68, n° 8, p. 2282–2286. doi: 10.1002/hlca.19850680823
Main files (1)
Article (Published version)
accessLevelRestricted
Identifiers
ISSN of the journal0018-019X
88views
0downloads

Technical informations

Creation03/14/2022 11:11:00 AM
First validation03/14/2022 11:11:00 AM
Update time03/16/2023 2:51:46 AM
Status update03/16/2023 2:51:46 AM
Last indexation02/01/2024 7:55:45 AM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack