36829-89-7Relevant academic research and scientific papers
CYCLONES IN THE DIELS-ALDER REACTION CATALYZED BY ALUMINUM CHLORIDE
Kiselev, V. D.,Shakirov, I. M.,Konovalov, A. I.
, p. 272 - 276 (2007/10/02)
A comparison was made of the kinetic parameters for the uncatalyzed and catalyzed ( with aluminum chloride ) Diels-Alder reaction between N-arylmaleimides and acrylic, methacrylic, and fumaric esters as dienophiles and phencyclone and tetracyclone as dienes.By thermochemical and spectrophotometric experiments it was shown that the aluminum chloride coordinates with the dienophile in a ratio of 1:1.With a larger concentration of the catalyst coordination also takes place at the carbonyl of the diene.For the complexes of N-arylmaleimides the rate constants for the reaction with free tetracyclone and phencyclone increase by not more than 60 times, those for the esters of the unsaturated acids increase by 300-600 times, whereas those in the reaction with anthracene increase by 1E5 times.The results are discussed from the standpoint of the change in the energy of the molecular orbitals of the reagents.
REACTIVITY OF 2,5-DIARYL-3,4-o,o-BIPHENYLENECYCLOPENTADIENONES IN THE DIENE SYNTHESIS REACTION WITH N-ARYLMALEIMIDES AND MALEIC ANHYDRIDE
Samuilov, Ya. D.,Nurullina, R. L.,Uryadova, L. F.,Konovalov, A. I.
, p. 1576 - 1581 (2007/10/02)
The reactivity of substituted phencyclones in the diene synthesis reaction with N-arylmaleimides and maleic anhydride was investigated.These reactions are of the "diene-donor, dienophile-acceptor" type.The selectivity of the reactions of the cyclones with imides is determined by the electronic character of the substituents in the dienophile. "Normal" selectivity is observed in the investigated reactions, and this is consistent with the idea that the reactivity in the given series is controlled not only by orbital donor-acceptor interactions but also by localization energies.
