110434-38-3Relevant academic research and scientific papers
Kinetics of carbenium ion additions to methylenecycloalkanes: Cycloalkyl cation stabilities are not predominantly controlled by strain
Roth,Schade,Mayr
, p. 169 - 172 (1994)
Kinetic investigations of the reactions of the (p-anisyl)phenylcarbenium tetrachloroborate (1 BCl4-) with methylenecycloalkanes (ring size 3-12 and 15) have been performed. The second-order rate constants correlate with the solvolysis rates of the corresponding cycloalkyl derivatives, though none of the ring carbons is rehybridized in the rate-determining step (electrophilic attack of 1 at the CC double bond). A simple explanation for the observed rate effects cannot be given, and it is claimed that the common rationalization of cycloalkyl solvolysis rates by differences of internal strain has to be modified.
Addition reactions of diarylcarbenium ions to 2-methyl-1-pentene: Kinetic method and reaction mechanism
Mayr, Herbert,Schneider, Reinhard,Schade, Christian,Bartl, J?rg,Bederke, Rainer
, p. 4446 - 4454 (2007/10/02)
A kinetic method that allows the determination of reactivities of carbenium ions toward alkenes is described: Diarylmethyl chlorides (1) are completely ionized by BCl3 in CH2Cl2 to give colored solutions of diarylcarbenium
Thermochemical Study of the Addition of Carbenium Ions to Alkenes
Schade, Christian,Mayr, Herbert,Arnett, Edward M.
, p. 567 - 571 (2007/10/02)
Scales of carbenium ion stabilities have been obtained from 1H NMR equilibrium studies of mixtures of partly ionized para-substituted diarylmethyl chlorides in CD2Cl2/BCl3 at -70 deg C and via calorimetric determination of the heats of ionization (ΔHi) of the alkyl chlorides (Ar2CHCl + BCl3 -> Ar2CH+BCl4-) in CH2Cl2/BCl3 at -70 deg C.The heats of the reactions of diarylmethyl tetrachloroborates with 2-methyl-1-pentene (Ar2CH+BCl4- + CH2=C(CH3)C3H7 -> Ar2CHCH2C(CH3)ClC3H7 + BCl3), which were determined by low-temperature calorimetry, increase from -53.1 kJ/mol for (H3CC6H4)2CH+BCl4- to -33.0 kJ/mol for the better stabilized (H3COC6H4)(H3CC6H4)CH+BCl4-.In contrast, the heats (ΔHa) of the Lewis acid catalyzed additions of the corresponding para-substituted diarylmethyl chlorides to 2-methyl-1-pentene are independent of the para substituents (ΔHa=-86.5 +/-2.7 kJ/mol).Similar values of ΔHa were obtained for the addition of p-anisylphenylmethyl chloride to trimethylethylene, styrene, β-methylstyrene, and isoprene. ΔHa is predominantly determined by the conversion of a ?(C=C) into a ?(C-C) bond, and the heats of addition of diarylmethyl tetrachloroborates to alkenes in CH2Cl2 are given by the equation ΔHb=(9.5 +/- 6.3 pKR+) kJ/mol.
