Dissertations / Theses on the topic 'Azadiene'

The bromination of alkene/epoxide mixtures leads to the fonnation of B,B'-dibromoethers (BrCR2CR20CR2CR2Br) [R=H,Me] and dibromoalkanes. The amount of B,B' -dibromoether fonned was optimised relative to the amount of dibromoalkane fonned by carrying jout the reaction in pentane at -78°C. The reaction is believed to proceed via a three step mechanism, two steps of which (the opening of bromonium ion by epoxide, and the opening of oxonium ion by Br) have been shown to occur stereospecifically. (Cinnamaldehydeanil)/tricarbonyliron(O) (4), (PhCHCHCHNPh)Fe(COh, a representative (l-azadiene )tricarbonyliron(O) complex can be prepared in 41 % yield by heating cinnamaldehydeanil (5) (PhCHCHCHNPh) with Fez(CO)9 (17). This yield could be improved to 82% by the use of ultrasound, or to 80% via a transfer reaction from a (l-oxadiene)tricarbonyliron(O) complex. l-Azadiene complexes could themselves be used as a source of -Fe(COh for a transfer reaction to butadiene ligands, the first reported use of (azadiene)tricarbonyliron(O) complexes in this way. (l-Azadiene)tricarbonyliron(O) was found to be unreactive with respect to Diels-Alder reactions. (2-Azadiene)tricarbonyliron(O) complexes (109) have never been reported. A series of 2-azadiene ligands (ArCHNCHCHCH3) [Ar = Ph- (114); Ar = 4-CIC6H4- (116); Ar = 4-MeOC6H4- (115)] were prepared, but complexation with Fe2(CO)9 (17) or Fe(CO)s (26) did not produce a tricarbonyliron(O) complex. Complexation of (115) with Fe2(CO)9 (17), however, produced a Fe2(CO)6 containing compound (118) [(4-MeO-C6H3-CH2NCHCHCH3)-Fe2(CO)6] in 10% yield.

The work of this Ph.D. thesis is an in depth study on [4+2] and [2+2] cycloaddition reactions of 1-(4-methylphenyl) and 1-benzyl-1,3-diaza-1,3-butadienes with different ketenes, usually generated from the corresponding acid halide in the presence of a base. Reaction with phenyl, diphenyl, chloro and ethoxycarbonylketenes are described and the mechanism involved is discussed. Moreover, thermal and photochemical ring expansion reactions of azetidinones to 5,6-dihydro-3H-pyrimidin-4-ones are studied. Finally, the [2+2] cycloaddition reactions of 1-benzyl-2,4-diphenyl-1,3-diaza-1,3-butadiene with some chiral ketenes, such as beta-(dimethylphenylsilyl)ketene, beta-menthoxyketene and Evans-Sjögren ketene are investigated. The results are analysed and rationalized also on the basis of computational calculations.

Lo scopo di questo lavoro è stato quello di studiare dettagliatamente la reattività dell’N-benzilossicarbonil-1-aza-butadiene, utilizzando diversi dienofili in reazioni di Diels-Alder catalitiche enantioselettive promosse da organocatalizzatori bifunzionali in grado di dare interazioni deboli come legami a idrogeno. Questo 1-azadiene infatti può dare in linea di principio sia prodotti derivanti da reazioni di Diels-Alder a domanda elettronica diretta in cui funge da diene, sia reazioni a domanda elettronica inversa in cui il doppio legame terminale dell’1-azadiene, maggiormente reattivo in quanto meno ingombrato, funge da olefina elettronricca (reazione di Povarov). Per effettuare questo studio sono stati provati vari dienofili tra cui olefine elettron povere bi- e monosostituite che portavano alla degradazione del diene; derivati della malimmide e del pirazolo che davano cilcloaddotti derivanti dalla classica cicloaddizione [4+2] Diels-Alder con ottime conversioni in modo altamente diastereoselettivo, ma bassi eccessi enantiomerici ed infine si sono provate diverse immine che portavano al cicloaddotto della reazione di Povarov con ottimi risultati in termini di conversione e buoni eccessi enantiomerici. Quest’ultima applicazione che permette la sintesi di interessanti prodotti variamente funzionalizzabili, sarà oggetto di studio in futuro per ottimizzare le condizioni della reazione.

Les etudes decrites dans cette these portent sur la reactivite des n-alkyl-2-cyano-1-azadienes dans la reaction de de diels-alder intramoleculaire et sur l'utilisation de ce procede pour la synthese des systemes indolizidines et indoloquinolizidines. La preparation des azadienes est realisee par traitement d'acrylamides ,-insatures avec l'anhydride triflique, suivi de l'addition de cyanure de lithium. Au cours de ce projet l'efficacite de ces cycloadditions a ete demontree, s'effectuant avec des rendements compris entre 63 et 92%. Dans le cas des indolizidines, une etude des etats de transition a ete realisee par modelisation moleculaire pour expliquer les selectivites endo et faciale observees. Grace a une analyse des resultats structuraux obtenus, il a ete demontre que lors de la localisation des etats de transition, il y a une deformation de la chaine reliant le diene au dienophile due a la minimisation des interactions 1, 3 allyliques. Cette deformation se manifestant par des torsions d'angles de valence ou d'angles diedres couteuses en energie. D'autre part, pour le cas des indoloquinolizidines, la formation de l'azadiene requiert la desactivation des groupes nucleophiles au voisinage des intermediaires o-triflyl imidates. Cependant, en presence de cyanure de tetrabutylammonium au lieu de cyanure de lithium, la reaction de la n-triflation qui est competitive a la o-triflation, est evite. Dans une autre approche, nous avons cherche a contourner le probleme de preparation de la 2-vinyltryptamine par une ouverture du cycle c de la tetrahydroharman

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CNPq, CAPES, FAPESB e INCT
O presente estudo traz reações regiosseletivas envolvendo enaminonas e sais de tetrafluorborato arenodiazônio como espécies eletrofílicas. Foram realizadas sínteses de enaminonas funcionalizadas, como as azoenaminonas, e compostos dela derivados. Dessa forma, ampliamos a quantidade de azocompostos derivados de enaminonas. As azoenaminonas são alcançadas via reação de acoplamento de sais de tetrafluorborato de arenodiazônio no carbono α-carbonílico de enaminonas, na presença de acetato de sódio. Baseando-se neste aspecto reacional, novas azoenaminonas foram sintetizadas, ampliaou-se o número de compostos azo e foram aperfeiçoados a síntese de seus derivados, os azadienos. No decorrer deste trabalho, foi possível racionalizar a síntese multicomponente para os 1-azadienos, provenientes da acetilação de azoenaminonas acíclicas derivadas da 4-amino-3-penten-2-ona. Foi proposta uma metodologia alternativa para a síntese tricomponente dos azadienos descritos na literatura. Nesta metodologia, que acontece “one-pot”, a enaminona acíclica sofre reação de acoplamento por sais de tetrafluorborato de arenodiazônio na presença do anidrido acético como solvente. Assim, foram testados diferentes sais de tetrafluorborato de arenodiazônio. Foram variados os padrões de substituição contidos no anel benzênico com a presença de grupos doadores, e/ou retiradores de elétrons. O grupo azo confere à molécula planaridade e permite que haja deslocamento de elétrons por sua estrutura, este aspecto peculiar possibilita que estes compostos apresentem atividade óptica não linear (ONL). A ONL pode ser mensurada utilizando cálculos teóricos semi-empíricos AM1. Uma vez apresentando potencialidade para ONL, o composto tende a apresentar propriedades que o tornam importantes, pois, podem ser utilizadas em tecnologias fotônicas. Dessa forma, a presença de grupos cromóforos tende a potencializar o efeito push-pull. Tal propriedade está diretamente relacionado com a hiperpolarizabilidade (β), propriedade que está diretamente relacionada a ONL. Com o intuito de contribuir com azocompostos análogos, realizou-se a síntese, caracterização e estudo solvatocrômico dos mesmos. O estudo solvatocrômico foi realizado obtendo-se espectros na região do ultravioleta-visível, identificando as principais bandas de absorção e tipos de transições eletrônicas envolvidas. Dessa forma, ampliação do escopo de novos azocompostos foi evidenciada, propondo uma nova metodologia de síntese de azadienos e um estudo solvatocrômico para os mesmos.
This report talks about regioselective reactions between enaminones and tetrafluorborate aryldiazone salts. Functionalized synthesis of enaminones, like azoenaminones, were developed and its derivatives compounds. The amount of azocompounds derivatives was amplified. The azoenaminones were obtained by coupling reactions of aryldiazone salt on the enaminone’s α- carbonyl carbon in the presence of sodium acetate. The sodium acetate, which contains on the reaction environment, neutralizes the tetrafluorboric acid from tetrafluorborate of aryldiazone that is produced by the reaction. Based on this reactional aspect, new azoenaminones were synthesized, the amount of azocompounds was amplified and also the syntheses of its derivatives– azodienes were improved. As the project was developed, was possible to rationalize the multicomponent synthesis to 1-azadienes from a reaction of acetylation of acyclic azoenaminones derivatives from 4- amine-3-penten-2-one. In addition to that an altenative methodology for the procedure described by the literature for tricomponent synthesis of azodienes was proposed. In that methodology which follows “one-pot reaction’s”, the acyclic enaminone pass through diazotization reaction starting from a reaction between aryldiazone salt and anidride acetic as a solvent. Then, different salts of aryldiazone tetrafluorborate were tested changing the substituition patterns that contains on the benzenic ring in the presence of electron donor groups and/or electron withdrawing groups. The azo group gives the molecule planarity and allows the movement of electrons happens because of its structure. This peculiar aspect allows this compounds to have optic non linear activity (ONL). The ONL might be measured by Photonic Technology. In the same way, the presence of chromophors groups tends to potencialize the effect “push-pull”. This characteristic is related to hiperpolarizability (β) which is straight related to ONL. In order to concur with analogues azocompounds, its synthesis, characterization and solvatochromic studies were developed. The solvatochromic studies were realized and the spectrums in gold-purple region were obtained and its absorption bands and eletronic transitions types involved were identified. Finally, the amplification of the scope of new azocompounds were reported and a new methodology of azodiene’s synthesis was proposed along to the solvatochromic study.

Ce travail de thèse est consacré à la synthèse de composés azotés biologiquement actifs s’inspirant notamment d’une réaction biosynthétique. Dans un premier temps, nos travaux avaient pour but de développer une nouvelle voie d’accès aux acides alpha-aminés par une réaction d’isomérisation énantiosélective d’imines. Après différentes études préliminaires, les meilleurs précurseurs d’acides alphaaminés par cette méthode que nous ayons identifiés sont les alpha céto amides. L’isomérisation 1,3 d’une imine formée à partir d’un alpha céto amide et de la diphénylméthanamine à l’aide de différents alcoolates chiraux a été réalisée. L’utilisation de l’alcoolate dérivé de la (+)-N-méthylpseudoéphédrine, employé en quantité sub-stœchiométrique, a permis d’obtenir l’alpha amino amide correspondant avec un excès énantiomérique de 67%. Il reste encore à mettre au point des conditions opératoires satisfaisantes pour la conversion de cet adduit en acide alpha aminé. L’étude de l’isomérisation 1,3 d’imines nous a permis de mettre en évidence une réaction de déshydrogénation 1,4 permettant d’accéder de façon originale à des 2-azadiènes et nécessitant la présence d’oxygène. Ainsi, plusieurs 2-azadiènes non activés ont été préparés par traitement basique d’imines issues de la condensation d’acétophénones et de diphénylméthanamine sous atmosphère d’air. Dans une dernière partie, l’étude de l’addition conjuguée d’une oxazolidinone chirale sur des alkylidènemalonates de dialkyle a été réalisée dans le but de développer une méthode d’accès à des acides alpha aminés. Les conditions opératoires mises au point ont permis d’obtenir une excellente diastéréosélectivité à partir de la plupart des alkylidènemalonates de dialkyle
This thesis work is devoted to the synthesis of biologically active nitrogen-containing compounds, particularly inspired by a biosynthetic reaction. Initially, our work aimed to develop a new pathway to a-amino acids using anenantioselective imine isomerization reaction. After various preliminary studies, the best precursors of a-amino acids that we have identified are a-keto amides. The 1,3isomerization of an imine formed from an a-keto amide and diphenylmethanamine using various chiral alkoxides was then conducted. The alkoxide derived from (+)-N-méthylpseudoéphédrine, employed in sub-stoichiometric quantities, allowed obtaining the corresponding a-amino amide with 67% enantiomeric excess. It still remains to develop satisfactory operating conditions for the conversion of this adduct to an a-amino acid.The study of the 1,3 isomerization of imines allowed us to bring to light a 1,4 dehydrogenation reaction, which allows an original access to 2-azadienes and which requires the presence of oxygen. Thus, several non-activated 2-azadienes have been prepared by basic treatment of imines derived from acetophenones anddiphenylmethanamine, under air atmosphere.In the last part, the study of the conjugate addition of a chiral oxazolidinone on dialkyl alkylidenemalonates was carried out, with the aim to develop a method of access to enantiopure b-amino acids. Reactions conditions developed allowed to obtain an excellent diastereoselectivity from most dialkyl alkylidenemalonates

Ce travail concerne principalement l'etude de reactions de diels alder de la p-chloro (bistrimethylsilyl) methylene phosphine avec divers dienes fonctionnalises riches et pauvres en electrons. Une voie d'acces nouvelle et relativement generale aux phosphabenzenes fonctionnalises est ainsi ouverte. Les limitations de la methode sont discutees. La derniere partie de ce travail met en evidence la possibilite de ene reactions avec la p-chloro (bistrimethylsilyl) methylene phosphine. Les enophiles sont des alcenes classiques ou des azadienes pour lesquels la ene reaction et non la reaction d'aza diels-alder est observee

Ce travail de thèse est consacré à la synthèse de composés azotés biologiquement actifs s'inspirant notamment d'une réaction biosynthétique. Dans un premier temps, nos travaux avaient pour but de développer une nouvelle voie d'accès aux acides α-aminés par une réaction d'isomérisation énantiosélective d'imines. Après différentes études préliminaires, les meilleurs précurseurs d'acides a-aminés par cette méthode que nous ayons identifiés sont les α-céto amides. L'isomérisation 1,3 d'une imine formée à partir d'un α-céto amide et de la diphénylméthanamine à l'aide de différents alcoolates chiraux a été réalisée. L'utilisation de l'alcoolate dérivé de la (+)-N-méthylpseudoéphédrine, employé en quantité sub-stoechiométrique, a permis d'obtenir l'α-amino amide correspondant avec un excès énantiomérique de 67%. Il reste encore à mettre au point des conditions opératoires satisfaisantes pour la conversion de cet adduit en acide α-aminé. L'étude de l'isomérisation 1,3 d'imines nous a permis de mettre en évidence une réaction de déshydrogénation 1,4 permettant d'accéder de façon originale à des 2-azadiènes et nécessitant la présence d'oxygène. Ainsi, plusieurs 2-azadiènes non activés ont été préparés par traitement basique d'imines issues de la condensation d'acétophénones et de diphénylméthanamine sous atmosphère d'air. Dans une dernière partie, l'étude de l'addition conjuguée d'une oxazolidinone chirale sur des alkylidènemalonates de dialkyle a été réalisée dans le but de développer une méthode d'accès à des acides β-aminés. Les conditions opératoires mises au point ont permis d'obtenir une excellente diastéréosélectivité à partir de la plupart des alkylidènemalonates de dialkyle.

Dissertação de Mestrado em Química apresentada à Faculdade de Ciências e Tecnologia
Steroids are a class of compounds that are widely distributed in nature and which exhibit a wide spectrum of biological activities. In addition to the typical high hormonal activity of steroids, they may also exhibit strong antimicrobial, anti-inflammatory and anticancer activity. Currently, structural modification of the steroid nucleus, particularly the introduction of heteroatoms or heterocycles, is a strategy successfully used in order to modulate its biological properties.The Organic Chemistry research group of the University of Coimbra conducted a study that led to the development of a new diastereoselective methodology to chiral penta- and hexacyclic steroids through an annulation mechanism of steroidal N-sulfonyl-1-azadiene with a range of ketones in the presence of catalytic pyrrolidine. In this way, we set out to explore this new synthetic route of obtaining new chiral penta- and hexacyclic steroids by extending to new steroid substrates and a wide range of carbonyl compounds, including aldehydes.The first chapter of this dissertation describes some relevant examples of the literature that highlight the chemical and biological properties of steroids. The synthesis of penta- and hexacyclic steroids is also described. Finally, a review of the literature underlying the hetero-Diels-Alder reaction as well as the participation of N-sulfonyl-1-azadienes in the reaction is presented.The second chapter describes the study of the reactivity of two steroidal N-sulfonyl-1-azadienes towards a range of ketones in the presence of a catalytic amount of pyrrolidine. Firstly, the reactivity of N-sulfonyl-1-azadiene derived from 16-DPA towards a range of ketones will be presented, as well as the subsequent transformation of functional groups of the products, leading to the synthesis of new hexacyclic steroids. The development of a synthetic pathway for the synthesis of a novel N-sulfonyl-1-azadiene derived from 16-dehydroprogesterone is also presented. The reaction of this derivative with a ketone in the presence of a catalytic amount of pyrrolidine originated a new chiral hexacyclic steroid.The third chapter describes the reactivity studies of the steroidal N-sulfonyl-1-azadienes derived from 16-DPA and 16-dehydroprogesterone with a range of aldehydes in the presence of pyrrolidine. Steroidal N-sulfonyl-1-azadienes were found to react with aldehydes by hetero-Diels-Alder reaction, contrary to that described for the ketone reaction. The reactivity observed allowed the synthesis of new chiral penta- and hexacyclic steroids, in a diastereoselective manner, with moderate yields.
Os esteroides são uma classe de compostos amplamente distribuídos na natureza e exibem um largo espetro de atividades biológicas. Para além da típica elevada atividade hormonal, os esteroides podem também exibir uma forte atividade antimicrobial, anti-inflamatória e anticancerígena. Atualmente, a modificação estrutural do núcleo esteroide, particularmente a introdução de heteroátomos ou heterociclos, é uma estratégia utilizada com sucesso para a modulação das suas propriedades biológicas.O grupo de Química Orgânica da Universidade de Coimbra realizou um estudo que levou ao desenvolvimento de uma nova metodologia para a síntese diastereosseletiva de esteroides quirais penta- e hexacíclicos através de um mecanismo de ciclização de um N-sulfonil-1-azadieno esteroidal com cetonas na presença de pirrolidina. Deste modo, propusemo-nos a explorar esta nova via sintética de obtenção de novos esteroides quirais penta- e hexacíclicos alargando a novos substratos esteroides e a um leque alargado de compostos carbonílicos, incluindo aldeídos.No primeiro capítulo desta dissertação são descritos alguns exemplos relevantes da literatura que evidenciam as propriedades químicas e biológicas dos esteroides. Descreve-se ainda a síntese de esteroides penta- e hexacíclicos. Por fim, é apresentada uma revisão da literatura subjacente à reação de hetero-Diels-Alder, bem como a participação de N-sulfonil-1-azadienos na reação.No segundo capítulo é descrito o estudo da reatividade de dois N-sulfonil-1-azadienos esteroidais com uma gama de cetonas na presença de quantidade catalítica de pirrolidina. Primeiramente será apresentada a reatividade do N-sulfonil-1-azadieno derivado do 16-DPA com uma gama de cetonas, bem como a posterior transformação de grupos funcionais dos produtos, o que levou à síntese de novos esteroides hexacíclicos. É ainda apresentado o desenvolvimento de uma via sintética para a síntese de um novo N-sulfonil-1-azadieno derivado da 16-desidroprogesterona. A reatividade deste derivado com uma cetona na presença de quantidade catalítica de pirrolidina deu origem a um novo esteroide hexacíclico quiral.No terceiro capítulo é descrito o estudo da reatividade dos N-sulfonil-1-azadienos esteroidais derivados do 16-DPA e da 16-desidroprogesterona com uma gama de aldeídos na presença de pirrolidina. Verificou-se que os N-sulfonil-1-azadienos esteroidais reagiram com aldeídos através de reação de hetero-Diels-Alder, contrariamente ao descrito para a reação com cetonas. A reatividade observada permitiu a síntese de novos esteroides penta- e hexacíclicos quirais de forma diastereosseletiva com rendimentos moderados.
FCT

碩士
中國醫藥大學
藥物化學研究所碩士班
100
Chemoselective microwave-assisted amidination was successfully developed to alternatively synthesize 1H-pyrazol-5-yl-N,N-dimethyl-formamidine and pyrazolyl-2-azadiene two classes compounds. All of the starting materials and resulting products were tested against NCI-H226, NPC-TW01, and Jurkat cancer cell lines to evaluate their difference in antiproliferative activities for realizing the structure activity relationship study. Following the SAR result, 1H-pyrazol-5-yl-N,N-dimethylformamidine compounds 2b, 2c and 2d possessed the best potent with IC50 values in low micromolar range. On the other hand, we found that the formyl group at C-4 position and the grafted amidinyl group in the main core of pyrazolic molecule were necessary for the inhibitory activity