{"id":113559,"date":"2018-03-11T10:41:03","date_gmt":"2018-03-11T10:41:03","guid":{"rendered":"https:\/\/www.deberes.net\/tesis\/sin-categoria\/asymmetric-organocatalytic-cascade-reactions\/"},"modified":"2018-03-11T10:41:03","modified_gmt":"2018-03-11T10:41:03","slug":"asymmetric-organocatalytic-cascade-reactions","status":"publish","type":"post","link":"https:\/\/www.deberes.net\/tesis\/estereoquimica-y-analisis-conformacional\/asymmetric-organocatalytic-cascade-reactions\/","title":{"rendered":"Asymmetric organocatalytic cascade reactions"},"content":{"rendered":"

Tesis doctoral de Garazi Talavera Urquijo <\/strong><\/h2>\n

Resumenen la presente memoria se recoge el trabajo de investigaci\u00f3n enmarcado en elempleo de aminas secundarias quirales como organocatalizadores para el dise\u00f1o dereacciones en cascada con el fin de obtener compuestos de inter\u00e9s con elevadorendimiento y control estereoqu\u00edmico. De esta manera, en primer lugar se ha puestoa punto una metodolog\u00eda para la s\u00edntesis de furanos mediante una reacci\u00f3n encascada aminocatal\u00edtica oxa-michael\/reacci\u00f3n ald\u00f3lica\/hemiacetalizaci\u00f3n entrealdeh\u00eddos , -insaturados y dihidroxiacetona combinando los modos de activaci\u00f3niminio y enamina. Asimismo, se ha demostrado la posibilidad de llevar a cabotransformaciones eficientes de manera selectiva sobre los aductos obtenidospermitiendo obtener un amplio abanico de compuestos, lo que pone de manifiesto elpotencial de esta metodolog\u00eda para la s\u00edntesis enantioselectiva de diversos buildingblocks quirales de inter\u00e9s en s\u00edntesis org\u00e1nica. La extensi\u00f3n de dicha estrategia aluso de -aminoacetofenona ha permitido obtener distintas -lactamasenantioenriquecidas con excelentes rendimientos.En segundo lugar, se ha puesto a punto una metodolog\u00eda enfocada a las\u00edntesis asim\u00e9trica de ciclobutanos sustituidos mediante una reacci\u00f3n formal decicloadici\u00f3n [2+2] entre aldeh\u00eddos , -insaturados enolizables y nitroalquenos -hidroximetil susutituidos. En este caso, se ha empleado un sistema catal\u00edticocompuesto por un derivado de difenilprolinol y una tiourea aquiral, haciendo as\u00ed usode la aminocat\u00e1lisis y la cat\u00e1lisis por formaci\u00f3n de enlaces de hidr\u00f3geno. De estemodo, se ha demostrado que la cooperaci\u00f3n de ambos modos de activaci\u00f3n permiteel desarrollo de dicha transformaci\u00f3n sint\u00e9tica con elevados rendimientos yexcelente estereocontrol.Abstractin this dissertation, our work on the study of chiral secondary amines aspromoters in enantioselective organocatalytic cascade reactions towards theasymmetric synthesis of different substituted hetero- and carbocycles is presented.In this sense, we have developed an efficient methodology for theconstruction of hexahydrofuro[3,4-c]furans containing four stereocenters by meansof an amine catalyzed oxa-michael\/aldol\/hemiacetalization cascade reaction byreacting different , -unsaturated aldehydes with dihydroxyacetone underiminium\/enamine catalysis. Remarkably, a high pka oxygen pro-nucleophile hasbeen employed as functionalized michael donor to initiate the conjugate process,which represents an important feature of this transformation. This methodology hasled to the formation of polysubstituted furofuranes in excellent yields and diastereoandenantioselectivities. Moreover, different related compounds can be accessedthrough the selective manipulation of the functionalities present within the obtainedadducts emphasising the potential of this methodology for the synthesis of usefulchiral building blocks. Additionally, this strategy has been extended to the use of nprotected–aminoacetophenone for the synthesis of -lactams through amichael\/hemiaminalization cascade sequence.On the other hand, we have set up an enantioselective formal [2+2]cycloaddition reaction between enolizable , -unsaturated aldehydes andnitroalkenes towards the synthesis of highly substituted cyclobutanes. In thisparticular case, the combination of an , -diphenylprolinol derivative and anachiral thiourea was employed as the catalytic system, which was shown as apowerful activation strategy for the development of this reaction, affording productsin high yields and with excellent stereocontrol.Laburpenadoktorego tesi honetan, estrategia organokatalitikoak aukeratu dira zenbaitinteres handiko konposatuen sintesi asimetrikoa aurrera eramateko. Zentzu honetan,kaskada erreakzioetan oinarritutako prozesuak diseinatu dira aminokatalizatzaileekeskaintzen duten aktibazio modu ezberdinak erabiliz etekin eta kontrolestereokimiko altuak lortuz.Lehenik, enantioaberastutako furofurano poliordezkatuak lortzeko sintesiaminokatalitikoa ikertu da dihidroxiazetona eta aldehido , -asegabetuak erabiliz.Kasu honetan, iminio eta enamina aktibazio motak konbinatu egin dira oxa-michael\/aldolika erreakzioa\/hemiazetalizazioa kaskada prozesu enantioselektibo etaeraginkor bat aurrera eramanez. Era berean, lortutako produktuen aldakortasunsintetikoak zenbait eraldaketa kimiko burutzea ahalbidetu du metodolog\u00eda honengarrantzi sintetikoa erakutsiz. Halaber, garatutako estrategia aminokatalitikoazabaltzeko asmoz, -aminoazetofenonaren erabilera frogatu da -laktamaezberdinak lortuz. Aldi berean, sintetizatutako heteroziklo hauek konposatu 1,4-dikarboniliko enantioaberats ezberdinetan eraldatu egin dira.Bestalde, [2+2] zikloadizio organokatalitiko formala aztertu da katalisikobalente eta ez kobalentea erabiliz. Horretarako, aminokatalizatzaile eta tioureazosatutako sistema katalitikoa aukeratu da, bi aktibazio modu hauen kooperazioaketekin eta kontrol estereokimiko altuak lortzea ahalbideratzen duela frogatuz.<\/p>\n

 <\/p>\n

Datos acad\u00e9micos de la tesis doctoral \u00abAsymmetric organocatalytic cascade reactions<\/strong>\u00ab<\/h3>\n
    \n
  • T\u00edtulo de la tesis:<\/strong>\u00a0 Asymmetric organocatalytic cascade reactions <\/li>\n
  • Autor:<\/strong>\u00a0 Garazi Talavera Urquijo <\/li>\n
  • Universidad:<\/strong>\u00a0 Pa\u00eds vasco\/euskal herriko unibertsitatea<\/li>\n
  • Fecha de lectura de la tesis:<\/strong>\u00a0 13\/12\/2012<\/li>\n<\/ul>\n

     <\/p>\n

    Direcci\u00f3n y tribunal<\/h3>\n
      \n
    • Director de la tesis<\/strong>\n
        \n
      • Efraim Reyes Mart\u00edn<\/li>\n<\/ul>\n<\/li>\n
      • Tribunal<\/strong>\n
          \n
        • Presidente del tribunal: Antonio m. Echavarren pablos <\/li>\n
        • rosario Fernandez fernandez (vocal)<\/li>\n
        • Juan Miguel Oyarbide garmendia (vocal)<\/li>\n
        • diego j. Cardenas morales (vocal)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

           <\/p>\n","protected":false},"excerpt":{"rendered":"

          Tesis doctoral de Garazi Talavera Urquijo Resumenen la presente memoria se recoge el trabajo de investigaci\u00f3n enmarcado en elempleo de […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"footnotes":""},"categories":[902,12909],"tags":[1384,196270,122359,225463,146756,11339],"class_list":["post-113559","post","type-post","status-publish","format-standard","hentry","category-estereoquimica-y-analisis-conformacional","category-pais-vasco-euskal-herriko-unibertsitatea","tag-antonio-m-echavarren-pablos","tag-diego-j-cardenas-morales","tag-efraim-reyes-martin","tag-garazi-talavera-urquijo","tag-juan-miguel-oyarbide-garmendia","tag-rosario-fernandez-fernandez"],"_links":{"self":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/posts\/113559","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/comments?post=113559"}],"version-history":[{"count":0,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/posts\/113559\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/media?parent=113559"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/categories?post=113559"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/tags?post=113559"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}