Racemic hemiacetals as oxygen-centered pronucleophiles triggering cascade 1, 4-addition/Michael reaction through dynamic kinetic resolution under iminium catalysis. Development and mechanistic insights

Orue, A. ; Uria, U. ; Roca-López, D. ; Delso, I. (Universidad de Zaragoza) ; Reyes, E. ; Carrillo, L. ; Merino, P. (Universidad de Zaragoza) ; Vicario, J. L.

Resumen: 2-Hydroxydihydropyran-5-ones behave as excellent polyfunctional reagents able to react with enals through oxa-Michael/Michael process cascade under the combination of iminium and enamine catalysis. These racemic hemiacetalic compounds are used as unconventional O-pronucleophiles in the initial oxa-Michael reaction, also leading to the formation of a single stereoisomer under a dynamic kinetic resolution (DKR) process. Importantly, by using ß-aryl or ß-alkyl substituted a, ß-unsaturated substrates as initial Michael acceptors either kinetically or thermodynamically controlled diastereoisomers were formed with high stereoselection through the careful selection of the reaction conditions. Finally, a complete experimental and computational study confirmed the initially proposed DKR process during the catalytic oxa-Michael/Michael cascade reaction and also explained the kinetic/thermodynamic pathway operating in each case.

Idioma: Inglés

DOI: 10.1039/c7sc00009j

Año: 2017

Publicado en: CHEMICAL SCIENCE 8, 4 (2017), 2904-2913
ISSN: 2041-6520

Factor impacto JCR: 9.063 (2017)

Categ. JCR: CHEMISTRY, MULTIDISCIPLINARY rank: 18 / 171 = 0.105 (2017) - Q1 - T1

Factor impacto SCIMAGO: 4.508 - Chemistry (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/ES/DGA/E10
Financiación: info:eu-repo/grantAgreement/ES/MICINN/CTQ2013-44367-C2-1-P
Financiación: info:eu-repo/grantAgreement/ES/MINECO/CTQ2014-52107-P
Financiación: info:eu-repo/grantAgreement/ES/MINECO-FEDER/CTQ2016-76155-R

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Química Orgánica (Dpto. Química Orgánica)