α-Hydroxy ketones as masked ester donors in Brønsted base catalyzed conjugate additions to nitroalkenes

The catalyst-controlled enantioselective direct addition reaction of enolizable esters and related carboxylic acid derivatives to p electrophiles remains a difficult synthetic transformation. In this study, the suitability of a-hydroxy ketones as ester equivalents capable of being activated by bifun...

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Detalles Bibliográficos
Autores: Olaizola, Iurre, Campano, Teresa E., Iriarte, Igor, Vera, Silvia, Mielgo, Antonia, García Castillo, Jesús María, Odriozola Ibarguren, José Manuel, Oiarbide, Mikel, Palomo, Claudio
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2018
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/47253
Acceso en línea:https://hdl.handle.net/2454/47253
Access Level:acceso abierto
Palabra clave:Addition
Asymmetric catalysis
Esters
Organocatalysis
Synthesis design
Descripción
Sumario:The catalyst-controlled enantioselective direct addition reaction of enolizable esters and related carboxylic acid derivatives to p electrophiles remains a difficult synthetic transformation. In this study, the suitability of a-hydroxy ketones as ester equivalents capable of being activated by bifunctional Brønsted base catalysts in the context of conjugate addition reactions to nitroolefins is demonstrated. The scope of the reaction, which affords the corresponding Michael adducts with very high stereoselectivity (diastereomeric ratio (d.r.) +95:5, up to 99% enantiomeric excess (ee)), and its limitations are explored, as is the aftermath elaboration of adducts into densely functionalized enantioenriched products.