How lewis acids catalyze diels–alder reactions

The Lewis acid(LA)-catalyzed Diels–Alder reaction between isoprene and methyl acrylate was investigated quantum chemically using a combined density functional theory and coupled-cluster theory approach. Computed activation energies systematically decrease as the strength of the LA increases along th...

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Detalles Bibliográficos
Autores: Vermeeren, Pascal, Hamlin, Trevor, Fernández López, Israel, Bickelhaupt, Matthias
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/101614
Acceso en línea:https://hdl.handle.net/20.500.14352/101614
Access Level:acceso abierto
Palabra clave:547
Química orgánica (Química)
2306 Química Orgánica
Descripción
Sumario:The Lewis acid(LA)-catalyzed Diels–Alder reaction between isoprene and methyl acrylate was investigated quantum chemically using a combined density functional theory and coupled-cluster theory approach. Computed activation energies systematically decrease as the strength of the LA increases along the series I2 < SnCl4 < TiCl4 < ZnCl2 < BF3 < AlCl3. Emerging from our activation strain and Kohn–Sham molecular orbital bonding analysis was an unprecedented finding, namely that the LAs accelerate the Diels–Alder reaction by a diminished Pauli repulsion between the p-electron systems of the diene and dienophile. Our results oppose the widely accepted view that LAs catalyze the Diels–Alder reaction by enhancing the donor–acceptor [HOMOdiene–LUMOdienophile] interaction and constitute a novel physical mechanism for this indispensable textbook organic reaction.