Understanding the Molecular Mechanism of Thermal and LA-Catalysed Diels-Alder Reactions between Cyclopentadiene and Isopropyl 3-Nitroprop-2-Enate

Ewa Dresler; Aneta Wróblewska; Radomir Jasiński

doi:10.3390/molecules28145289

Understanding the Molecular Mechanism of Thermal and LA-Catalysed Diels-Alder Reactions between Cyclopentadiene and Isopropyl 3-Nitroprop-2-Enate

Molecules. 2023 Jul 8;28(14):5289. doi: 10.3390/molecules28145289.

Authors

Ewa Dresler¹, Aneta Wróblewska², Radomir Jasiński³

Affiliations

¹ Łukasiewicz Research Network-Institute of Heavy Organic Synthesis "Blachownia", Energetyków 9, 47-225 Kędzierzyn-Koźle, Poland.
² Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland.
³ Institute of Organic Chemistry and Technology, Cracow University of Technology, Warszawska 24, 31-155 Cracow, Poland.

Abstract

The molecular mechanism of the Diels-Alder reaction with the participation of cyclopentadiene and isopropyl 3-nitroprop-2-enate was examined based on wb97xd/6-311+G(d) (PCM) quantum chemical calculations. It was found that the type of mechanism for the conversion of addends depends significantly on the reaction conditions. In less-polar environments, a one-step polar mechanism is realised. In more polar solvents, the formation of "extended"-type zwitterionic intermediates is possible. In contrast, in the presence of an LA-type catalyst, the one-step mechanisms are replaced by respective stepwise mechanisms with zwitterionic or heterocyclic intermediates.

Keywords: DFT calculations; Diels–Alder reaction; molecular electron density theory; molecular mechanism; nitroalkene.

Grants and funding

This research received no external funding.