60992 20190709135532.0 doi 10.1039/c7sc00009j sideral 98569 ART-2017-98569 eng Orue, A. Racemic hemiacetals as oxygen-centered pronucleophiles triggering cascade 1, 4-addition/Michael reaction through dynamic kinetic resolution under iminium catalysis. Development and mechanistic insights 2017 Access copy available to the general public Unrestricted 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. info:eu-repo/grantAgreement/ES/DGA/E10 info:eu-repo/grantAgreement/ES/MICINN/CTQ2013-44367-C2-1-P info:eu-repo/grantAgreement/ES/MINECO/CTQ2014-52107-P info:eu-repo/grantAgreement/ES/MINECO-FEDER/CTQ2016-76155-R info:eu-repo/semantics/openAccess by-nc http://creativecommons.org/licenses/by-nc/3.0/es/ 9.063 2017 CHEMISTRY, MULTIDISCIPLINARY 18 / 171 = 0.105 2017 Q1 T1 4.508 2017 Chemistry (miscellaneous) 2017 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Uria, U. (orcid)0000-0002-5288-9345 Roca-López, D. (orcid)0000-0001-8355-2289 Delso, I. Universidad de Zaragoza Reyes, E. Carrillo, L. (orcid)0000-0002-2202-3460 Merino, P. Universidad de Zaragoza Vicario, J. L. 2013 765 Universidad de Zaragoza Dpto. Química Orgánica Área Química Orgánica 8, 4 (2017), 2904-2913 Chem. sci. CHEMICAL SCIENCE 2041-6520 839687 http://zaguan.unizar.es/record/60992/files/texto_completo.pdf Versión publicada 116408 http://zaguan.unizar.es/record/60992/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:60992 articulos driver 2019-07-09-12:02:59 ARTICLE