Iridium-catalyzed isomerization of N-sulfonyl aziridines to allyl amines

The Crabtree's reagent catalyzes the isomerization of N-sulfonyl 2,2-disubstituted aziridines to allyl amines. The selectivity of allyl amine vs imine is very high (up to 99/1). The unprecedented isomerization takes place in mild conditions without activation of the catalyst by hydrogen. The me...

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Detalles Bibliográficos
Autores: Cabré, Albert|||0000-0003-4367-2635, Sciortino, Giuseppe|||0000-0001-9657-1788, Ujaque, Gregori|||0000-0001-5896-9998, Verdaguer, Xavier|||0000-0002-9229-969X, Lledós, Agustí|||0000-0001-7909-422X, Riera, Antoni|||0000-0001-7142-7675
Tipo de recurso: artículo
Fecha de publicación:2018
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:279246
Acceso en línea:https://ddd.uab.cat/record/279246
https://dx.doi.org/urn:doi:10.1021/acs.orglett.8b02450
Access Level:acceso abierto
Palabra clave:Allyl group
Amines
Aziridines
Catalysts
Isomerization
Descripción
Sumario:The Crabtree's reagent catalyzes the isomerization of N-sulfonyl 2,2-disubstituted aziridines to allyl amines. The selectivity of allyl amine vs imine is very high (up to 99/1). The unprecedented isomerization takes place in mild conditions without activation of the catalyst by hydrogen. The mechanism has been studied computationally by DFT calculations; instead of the usual hydrogenation of COD, the catalytic species is formed by a loss of the pyridine ligand. Approaching of aziridine to this unsaturated species leads to a carbocation intermediate through a low energy barrier. A metal-mediated tautomerization involving sequentially γ-H elimination and N-H reductive elimination affords selectively the allyl amine. The readiness of the CγH bond to participate in the H elimination step accounts for the selectivity toward the allyl amine product.