23719-88-2Relevant articles and documents
First N-alkyl heterolysis of tertiary benzamides in neutral conditions
Auzeil, Nicolas,Tomas, Alain,Fleury, Maurice-Bernard,Largeron, Martine
, p. 8781 - 8785 (2000)
Tertiary benzamides 1-4 bearing a tricyclopropylmethyl substituent were synthesized and found to undergo rapid alkyl-nitrogen heterolysis at pH 7. X-Ray diffraction structural data for these amides revealed that their ability to give N-alkyl fission was not induced by the pyramidalization of the nitrogen atom, in contrast to what has been observed in the case of N-acyl cleavage (hydrolysis). (C) 2000 Elsevier Science Ltd.
Ruthenium-catalyzed hydroarylation of methylenecyclopropanes through C-H bond cleavage: Scope and mechanism
Ackermann, Lutz,Kozhushkov, Sergei I.,Yufit, Dmitry S.
supporting information, p. 12068 - 12077 (2012/10/29)
Intermolecular hydroarylation reactions of highly strained methylenecyclopropanes 2-phenylmethylenecyclopropane (1), 2,2- diphenylmethylenecyclopropane (2), methylenespiropentane (3), bicyclopropylidene (4), (dicyclopropylmethylene)cyclopropane (5), and benzhydrylidenecyclopropane (6) through C-H bond functionalization of 2-phenylpyridine (7 a) and other arenes with directing groups were studied. The reaction was very sensitive to the substitution on the methylenecyclopropanes. Although these transformations involved (cyclopropylcarbinyl)-metal intermediates, substrates 1 and 4 furnished anti-Markovnikov hydroarylation products with complete conservation of all cyclopropane rings in 11-93 % yield, whereas starting materials 3 and 5 were inert toward hydroarylation. Methylenecyclopropane 6 formed the products of formal hydroarylation reactions of the longest distal C-C bond in the methylenecyclopropane moiety in high yield, and hydrocarbon 2 afforded mixtures of hydroarylated products in low yields with a predominance of compounds that retained the cyclopropane unit. As byproducts, Diels-Alder cycloadducts and self-reorganization products were obtained in several cases from substrates 1-3 and 5. The structures of the most important new products have been unambiguously determined by X-ray diffraction analyses. On the basis of the results of hydroarylation experiments with isotopically labeled 7 a-[D5], a plausible mechanistic rationale and a catalytic cycle for these unusual ruthenium-catalyzed hydroarylation reactions have been proposed. Arene-tethered ruthenium-phosphane complex 53, either isolated from the reaction mixture or independently prepared, did not show any catalytic activity. Copyright
Efficient Br?nsted acid catalyzed hydrations and hydroaminations of (dicyclopropylmethylene)cyclopropane
Ackermann, Lutz,Kozhushkov, Sergei I.,Yufit, Dmitry S.,Marek, Ilan
scheme or table, p. 1515 - 1518 (2011/08/03)
(Dicyclopropylmethylene)cyclopropane underwent efficient Br?nsted acid catalyzed hydrations and hydroaminations with H2O and basic amines, respectively, occurring with conservation of all three cyclopropane rings. Georg Thieme Verlag Stuttgart
Influence of carbocation stability in the gas phase on solvolytic reactivity: Beyond bridgehead derivatives
Abboud, Jose-Luis M.,Alkorta, Ibon,Davalos, Juan Z.,Mueller, Paul,Quintanilla, Esther,Rossier, Jean-Claude
, p. 3786 - 3796 (2007/10/03)
The intrinsic gas-phase stability of bicyclic secondary carbocations has been determined by Dissociative Proton Attachment of chlorides and alcohols, respectively. From these data, Gibbs free energies for hydride transfer relative to 1-adamantyl (ΔrG°(8,exp)) are derived after application of appropriate leaving group corrections, and good agreement with theoretical values, (ΔrG°(8,comp)), calculated at the G2(MP2) or MP2/6-311G(d,p) level, is reached (Table 1). The relative rate constants for solvolysis (log(k/k0)) of the bicyclic secondary derivatives correlate with the stabilities of the respective carbocations in the same manner as tertiary bridgehead derivatives, but simple monoderivatives and acyclic derivatives solvolyze faster than predicted on the grounds of the ion stabilities. The corresponding stabilities of cyclopropyl- and benzyl-substituted carbocations have been obtained by a combination of experimental and computational data available in the literature with computational methods. Correlation of the rate constants for solvolysis vs ion stabilities for these compounds reveals a trend similar to that observed for bridgehead derivatives, but with much more scatter, which is attributed to nucleophilic solvent participation and/or nucleophilic solvation.
