Quantum chemical study of intramolecular rearrangements in 3-allyl-3-methyl-1,2-diphenylcyclopropene

Autor: Ruslan M. Minyaev, Galina A. Dushenko, Igor E. Mikhailov, O. I. Mikhailova, Vladimir I. Minkin
Rok vydání: 2021
Předmět:
Zdroj: Russian Chemical Bulletin. 70:699-705
ISSN: 1573-9171
1066-5285
DOI: 10.1007/s11172-021-3139-x
Popis: 3-Allyl-3-methyl-1,2-diphenylcyclopropene (1) and 3-allyl-2-methyl-1,3-diphenylcyclopropene (2) were shown by the DFT B3LYP/6-311++G(d,p) method to interconvert with the energy barriers ΔE≠ZPE(1→2) = 35.6 kcal mol−1 and ΔE≠ZPE(2→1) = 31.9 kcal mol−1via the Cope rearrangement to form an intermediate. This barrier is capable of transiting to stable 1,2-diphenyl-6-methyltricyclo[2.2.0.0]hexane with the barrier of ΔE≠ZPE = 11.8 kcal mol−1via synchronous processes of five-membered ring inversion and ring closure. The calculated higher barriers for the alternative concerted 1,3- and 3,3-sigmatropic shifts of the allyl group (ΔE≠ZPE = 39.9–57.0 kcal mol−1) indicate the energetic preference of the aforementioned pathway in accord with the experimental data.
Databáze: OpenAIRE
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