title: Rearrangements of 3-aryl-substituted cyclopropenyl anions and the gas-phase acidity of 3-(4-methylphenyl)cyclopropene.
abstract: 3-(4-Methylphenyl)-3-trimethylsilylcyclopropene and 3-(4-trifluoromethylphenyl)-3-trimethylsilylcyclopropene react with fluoride ion in the gas phase to afford 6-substituted 3-indenyl anions via a spontaneous rearrangement of their corresponding cyclopropenyl anions. These isomerizations led us to reinvestigate the reported gas-phase generation of 1,2,3-triphenylcyclopropenyl anion, and contrary to the previous study, a similar rearrangement to 1,2-diphenyl-1-indenyl anion is observed. Despite the instability of 3-aryl-3-cyclopropenyl anions, we were able to measure the acidity of 3-(4-methylphenyl)cyclopropene at the allylic position (delta H(o)acid = 398.6 +/- 1.4 kcal/mol) by the DePuy kinetic method. Ab initio calculations on the structures and energies of mono- and triaryl-substituted cyclopropenyl anions also are presented.
authors: Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors: K M
authors: KM
authors: Broadus
authors: S
authors: S
authors: Han
authors: S R
authors: SR
authors: Kass