title: Hydrazones as Singular Reagents in Asymmetric Organocatalysis.
abstract: This Minireview summarizes strategies and developments regarding the use of hydrazones as reagents in asymmetric organocatalysis, their distinct roles in nucleophile-electrophile, cycloaddition, and cyclization reactions. The key structural elements governing the reactivity of these reagents in a preferred pathway will be discussed, as well as their different interactions with organocatalysts, leading to diverse activation modes. Along these studies, the synthetic equivalence of N-monoalkyl, N,N-dialkyl, and N-acyl hydrazones with several synthons is also highlighted. Emphasis is also put on the mechanistic studies performed to understand the observed reactivities. Finally, the functional group transformations performed from the available products has also been analyzed, highlighting the synthetic value of these methodologies, which served to access numerous families of valuable multifunctional compounds and nitrogen-containing heterocycles.
authors.affiliation: Instituto de Investigaciones Químicas (CSIC-US) and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Avda. Américo Vespucio, 49, 41092, Sevilla, Spain).
authors.forename: María
authors.identifier: http://orcid.org/0000-0003-1131-5916
authors.initials: M
authors.lastname: de Gracia Retamosa
authors.affiliation: Departamento de Química Orgánica, Universidad de Sevilla and Centro de Innovación Avanzada (ORFEO-CINQA), C/Prof. García González, 1, 41012, Sevilla, Spain.
authors.forename: Esteban
authors.initials: E
authors.lastname: Matador
authors.affiliation: Departamento de Química Orgánica, Universidad de Sevilla and Centro de Innovación Avanzada (ORFEO-CINQA), C/Prof. García González, 1, 41012, Sevilla, Spain. dmonge@us.es.
authors.forename: David
authors.identifier: http://orcid.org/0000-0001-8007-4111
authors.initials: D
authors.lastname: Monge
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
authors.affiliation: Departamento de Química Orgánica, Universidad de Sevilla and Centro de Innovación Avanzada (ORFEO-CINQA), C/Prof. García González, 1, 41012, Sevilla, Spain. ffernan@us.es.
authors.forename: Rosario
authors.identifier: http://orcid.org/0000-0002-1755-1525
authors.initials: R
authors.lastname: Fernández
keywords: Brønsted acids; asymmetric organocatalysis; formylation/acylation; hydrazones; hydrogen bonds; nitrogen heterocycles