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Updated: Nov 6, 2025

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Published on: June 21, 2017
Are There Only Fold Catastrophes in the Diels-Alder Reaction Between Ethylene and 1,3-Butadiene?
Leandro Ayarde-Henríquez1, Cristian Guerra1, Mario Duque-Noreña1
1Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Universidad Andres Bello, Avenida República 275, 8370146 Santiago, Chile.
Abstract:
This work revisits the topological characterization of the Diels-Alder reaction between 1,3-butadiene and ethylene. In contrast to the currently accepted rationalization, we here provide strong evidence in support of a representation in terms of seven structural stability domains separated by a sequence of 10 elementary catastrophes, but all are only of the fold type (F and F†), that is, C4H6 + C2H4:1-7-[FF]F[F†F†][F†F†][FF]F†-0: C6H10. Such an unexpected finding provides fundamental new insights opening simplifying perspectives concerning the rationalization of the CC bond formation in pericyclic reactions in terms of the simplest Thom's elementary catastrophe, namely, the one-(state) variable, one-(control) parameter function.
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