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Studies on Thermosetting Resin Blends: Bispropargyl Ether-Bismaleimide
Published in Didier Rouxel, Sabu Thomas, Nandakumar Kalarikkal, Sajith T. Abdulrahman, Advanced Polymeric Materials, 2022
J. Dhanalakshmi, K. G. Sudhamani, C. T. Vijayakumar
Loustalot and Sanglar [29] studied the kinetic and polymerization mechanism of a series of monofunctional propargylic compounds. The results obtained have shown that the reaction starts by intramolecular ring formation (Claisen rearrangement). Based on a set of consistent physicochemical data, a reaction mechanism for these systems and a kinetic model of polymerization in the molten state can be proposed, corresponding to the formation of the first species before the gel point.
Gold(I)-assisted catalysis – a comprehensive view on the [3,3]-sigmatropic rearrangement of allyl acetate
Published in Molecular Physics, 2018
Marek Freindorf, Dieter Cremer, Elfi Kraka
Gold-catalysed sigmatropic rearrangements have been successfully employed in gold catalysis over the past decade [36]. However, not all mechanistic details of these processes are yet fully understood [21]. The Claisen rearrangement, introduced by Ludwig Claisen in 1902 [37], describes the [3,3]-sigmatropic rearrangement of allyl vinyl ethers leading to the preparation of γ, δ-unsaturated carbonyl compounds under the influence of heat. The synthetic potential of the Claisen rearrangement and related reactions has stimulated the interest of several generations of chemists to improve the yield of the rearrangement products, to shorten the reaction time and to perform the rearrangement under milder conditions to prevent undesired competitive side reactions and the decomposition of the starting materials and/or products. Claisen reported in his original paper [37] the apparent catalytic effect of ammonium chloride on the Claisen rearrangement, which was confirmed in 1963 [38]. Since then, numerous other substances including transition metal complexes have been tested as well as different environmental conditions, e.g. solvent effects, regarding their efficiency to catalyse the Claisen rearrangement and related sigmatropic shift reactions, to accelerate the reaction rates, and to increase the product specificity [36,39].