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Hydrazides and hydrazones as versatile Michael-Donors for iminium-catalyzed conjugate addition reactions

396 : il., graf.

Idioma:	English English
Publicación:	2014
Materia:	asymmetric synthesis organocatalysis Michael reaction heterocycles hydrazines hydrazones pyrazolines dihydropyridazines umpolung
Acceso electrónico:	http://hdl.handle.net/10810/11366

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id	addi-10810-11366
recordtype	addi
spelling	addi-10810-113662017-04-06T15:05:17Zcom_10810_12140Tesis Doctoralescom_10810_91INVESTIGACIÓNcol_10810_12145TD-Ciencias Hydrazides and hydrazones as versatile Michael-Donors for iminium-catalyzed conjugate addition reactions Fernández Chento, Maitane Vicario Hernando, José Luis Reyes Martín, Efraim Química Orgánica II/Kimika Organikoa II asymmetric synthesis organocatalysis Michael reaction heterocycles hydrazines hydrazones pyrazolines dihydropyridazines umpolung 396 : il., graf. In the work compiled in this thesis is presented a series of strategies that have been studied and have lead to the asymmetric synthesis of useful building blocks in high yields and stereochemical control. These are reliant on the use of chiral secondary amines as the element that induces stereocontrol, where the activation of the substrate is based on the formation of an iminium ion intermediate within the catalytic cycle. In this sense, it has been demonstrated that, under this type of activation, hydrazides and hydrazones are efficient and versatile reagents that can be used as Michael donors in conjugate addition reactions.Thus, the performance of these hydrazide and hydrazone reagents as N-donors has been initially tested. In this context, two different aza-Michael initiated cascade reactions have been studied, using either N,N¿-disubstituted hydrazides or hydrazones derived from pyruvaldehyde in the reaction with -unsaturated aldehydes. Furthermore, the synthetic versatility of the products obtained has allowed a series of transformations to be performed, which is highlighted in the synthesis of valuable adducts (e.g. pyrazolines, pyrazolidinones or 1,3-diamines).On the other hand, the ability of hydrazones to act C-pro-nucleophiles for the same type of reaction has also been demonstrated. In this sense, the conjugate addition reaction between N-monosubstituted hydrazones and various enals via iminium activation has been studied, confirming that hydrazones containing an electron-withdrawing group at the azomethine position undergo this process in a highly efficient manner. Moreover, the importance of this methodology has been highlighted by the synthesis of a series of 1,4-dicarbonyl compounds, verifying that hydrazones can behave as acyl anion equivalents. 2014-02-06T07:18:49Z 2014-02-06T07:18:49Z 2014-02-06T07:18:49Z 2012-09-25 2013-11-20T09:22:57Z 2012-09-25 info:eu-repo/semantics/doctoralThesis http://hdl.handle.net/10810/11366 139894 478 eng en info:eu-repo/semantics/openAccess (c) MAITANE FERNANDEZ CHENTO, 2012
external_data_source	Addi
institution	Digital
collection	Addi
language	English English
topic	asymmetric synthesis organocatalysis Michael reaction heterocycles hydrazines hydrazones pyrazolines dihydropyridazines umpolung
spellingShingle	asymmetric synthesis organocatalysis Michael reaction heterocycles hydrazines hydrazones pyrazolines dihydropyridazines umpolung Fernández Chento, Maitane Hydrazides and hydrazones as versatile Michael-Donors for iminium-catalyzed conjugate addition reactions
description	396 : il., graf.
author_additional	Vicario Hernando, José Luis
author	Fernández Chento, Maitane
title	Hydrazides and hydrazones as versatile Michael-Donors for iminium-catalyzed conjugate addition reactions
title_short	Hydrazides and hydrazones as versatile Michael-Donors for iminium-catalyzed conjugate addition reactions
title_full	Hydrazides and hydrazones as versatile Michael-Donors for iminium-catalyzed conjugate addition reactions
title_fullStr	Hydrazides and hydrazones as versatile Michael-Donors for iminium-catalyzed conjugate addition reactions
title_full_unstemmed	Hydrazides and hydrazones as versatile Michael-Donors for iminium-catalyzed conjugate addition reactions
title_sort	hydrazides and hydrazones as versatile michael-donors for iminium-catalyzed conjugate addition reactions
publishDate	2014
url	http://hdl.handle.net/10810/11366
_version_	1735862640537763840

Hydrazides and hydrazones as versatile Michael-Donors for iminium-catalyzed conjugate addition reactions

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