ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19850680823
