title: Regioselectivity Change in the Organocatalytic Enantioselective (3+2) Cycloaddition with Nitrones through Cooperative Hydrogen-Bonding Catalysis/Iminium Activation.
abstract: The reaction of nitrones with enals through iminium activation can be modulated by using cooperative hydrogen-bonding catalysis to induce the participation of a nitrone ylide (C-N-C) instead of the classical C-N-O dipole. As a consequence, N-hydroxypyrrolidines are obtained, rather than the expected isoxazolidines. The reaction proceeds smoothly and high enantioselectivities are observed in all cases. By using the appropriate substrate, polysubstituted pyrrolidines incorporating quaternary stereocenters can be efficiently prepared.
authors.affiliation: Department of Organic Chemistry II, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain.
authors.forename: Liher
authors.initials: L
authors.lastname: Prieto
authors.affiliation: Laboratorio de Síntesis Asimétrica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-CSIC, Campus San Francisco, 5009, Zaragoza, Spain.
authors.forename: Veronica
authors.initials: V
authors.lastname: Juste-Navarro
authors.affiliation: Department of Organic Chemistry II, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain.
authors.forename: Uxue
authors.initials: U
authors.lastname: Uria
authors.affiliation: Laboratorio de Síntesis Asimétrica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-CSIC, Campus San Francisco, 5009, Zaragoza, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Delso
authors.affiliation: Department of Organic Chemistry II, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain.
authors.forename: Efraim
authors.initials: E
authors.lastname: Reyes
authors.affiliation: Laboratorio de Síntesis Asimétrica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-CSIC, Campus San Francisco, 5009, Zaragoza, Spain.
authors.forename: Tomas
authors.initials: T
authors.lastname: Tejero
authors.affiliation: Department of Organic Chemistry II, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain.
authors.forename: Luisa
authors.initials: L
authors.lastname: Carrillo
authors.affiliation: Laboratorio de Síntesis Asimétrica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-CSIC, Campus San Francisco, 5009, Zaragoza, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Merino
authors.affiliation: Department of Organic Chemistry II, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain.
authors.forename: Jose L
authors.identifier: http://orcid.org/0000-0001-6557-1777
authors.initials: JL
authors.lastname: Vicario
keywords: asymmetric catalysis; cycloaddition; nitrones; organocatalysis; pyrrolidines