title: Asymmetric organocatalytic synthesis of tertiary azomethyl alcohols: key intermediates towards azoxy compounds and α-hydroxy-β-amino esters.
abstract: A series of peracylated glycosamine-derived thioureas have been synthesized and their behavior as bifunctional organocatalysts has been tested in the enantioselective nucleophilic addition of formaldehyde tert-butyl hydrazone to aliphatic α-keto esters for the synthesis of tertiary azomethyl alcohols. Using the 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-β-d-glucosamine derived 3,5-bis-(trifluoromethyl)phenyl thiourea the reaction could be accomplished with high yields (75-98%) and moderate enantioselectivities (50-64% ee). Subsequent high-yielding and racemization-free tranformations of both aromatic- and aliphatic-substituted diazene products in a one pot fashion provide a direct entry to valuable azoxy compounds and α-hydroxy-β-amino esters.
authors.affiliation: Instituto de Investigaciones Químicas (CSIC-US) and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Avda. Américo Vespucio, 49, 41092 Sevilla, Spain. jmlassa@iiq.csic.es.
authors.forename: José A
authors.initials: JA
authors.lastname: Carmona
authors.affiliation: Departamento de Química Orgánica, Universidad de Sevilla and Centro de Innovación en Química Avanzada (ORFEO-CINQA), C/ Prof. García González, 1, 41012 Sevilla, Spain. dmonge@us.es ffernan@us.es.
authors.forename: Gonzalo de
authors.initials: G
authors.lastname: Gonzalo
authors.affiliation: Departamento de Química Orgánica, Universidad de Sevilla and Centro de Innovación en Química Avanzada (ORFEO-CINQA), C/ Prof. García González, 1, 41012 Sevilla, Spain. dmonge@us.es ffernan@us.es.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Serrano
authors.affiliation: Instituto de Investigaciones Químicas (CSIC-US) and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Avda. Américo Vespucio, 49, 41092 Sevilla, Spain. jmlassa@iiq.csic.es.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Crespo-Peña
authors.affiliation: Instituto de Investigaciones Químicas (CSIC-US) and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Avda. Américo Vespucio, 49, 41092 Sevilla, Spain. jmlassa@iiq.csic.es.
authors.forename: Michal
authors.initials: M
authors.lastname: Šimek
authors.affiliation: Departamento de Química Orgánica, Universidad de Sevilla and Centro de Innovación en Química Avanzada (ORFEO-CINQA), C/ Prof. García González, 1, 41012 Sevilla, Spain. dmonge@us.es ffernan@us.es.
authors.forename: David
authors.initials: D
authors.lastname: Monge
authors.affiliation: Departamento de Química Orgánica, Universidad de Sevilla and Centro de Innovación en Química Avanzada (ORFEO-CINQA), C/ Prof. García González, 1, 41012 Sevilla, Spain. dmonge@us.es ffernan@us.es.
authors.forename: Rosario
authors.initials: R
authors.lastname: Fernández
authors.affiliation: Instituto de Investigaciones Químicas (CSIC-US) and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Avda. Américo Vespucio, 49, 41092 Sevilla, Spain. jmlassa@iiq.csic.es.
authors.forename: José M
authors.identifier: http://orcid.org/0000-0003-1772-2723
authors.initials: JM
authors.lastname: Lassaletta