Anon su

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Bunrit, Anon. Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi. Stockholm University. (Joseph Samec). ripl2016.eu?pid=diva Anon Bunrit, Christian Dahlstrand, Sandra K. Olsson, Pemikar Srifa, Genping Huang, Andreas . Länkar. Al-anon, för familjer till beroende. ripl2016.eu Bona via, för barn till beroende. ripl2016.eu Nordhemskliniken. ripl2016.eu

Anon su -

The thesis is divided into two parts, describing three different catalytic systems. Simultaneously, the oxo group of phosphinic acid operates as a base abstracting the nucleophilic proton and thus enhancing the nucleophilicity. We herein report a Fe OTf 3 -catalyzed stereospecific substitution of the hydroxyl OH group in secondary and tertiary alcohols by N- , and O- centered nucleophiles to generate synthetically precious enantioenriched pyrrolidines, tetrahydrofuran, 1,2,3,4-tetra-hydroquinolines, and chromanes. Rate-order determination indicated that the reaction follows first-order dependence with respect to the catalyst, the internal nucleophile, and the internal electrophile. The hydroxyl groups of aryl, allyl, and alkyl alcohols were substituted by the attack of O - and N -centered nucleophiles, to provide five- and six-membered heterocycles in up to excellent yields with high enantiospecificities.

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Low - Anon Competition and catalyst-substrate interaction experiments demonstrated that this transformation proceeds via an S N 2-type reaction pathway. Samec, Joseph, Profressor Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi. This reaction will open up new atom efficient techniques that enable alcohols to be used as nucleofuges in substitution reactions in the future. Rate order determination shows first-order dependences in catalyst, internal nucleophile, and electrophile concentrations, however, independence on external nucleophile and electrophile. The thesis is divided into two parts, describing three different catalytic systems. The corresponding amines were further transformed by a one-pot ring-closing metathesis and aromatization reaction to afford β -substituted pyrroles with linear and branched alkyl, benzyl, and aryl groups in overall moderate to good yields. By addition of ferric chloride to the reaction mixture, a selective aromatization to yield the corresponding pyrroles substituted in the beta-position was achieved. Competition and catalyst-substrate interaction experiments demonstrated that this transformation proceeds via an S N 2-type reaction pathway. The hydroxyl groups of aryl, allyl, and alkyl alcohols were substituted by the attack of O - and N -centered nucleophiles, to provide five- and six-membered heterocycles in up to excellent yields with high enantiospecificities. Experimental studies showed that phosphinic acid does not promote S N 1 reactivity. The procedure opens up new atom efficient technique for catalytic stereospecific reactions that allow easily accessible stereogenic secondary and tertiary alcohols to be considered as substrates in substitution reactions. Mechanistic studies revealed that the intramolecular substitution reaction proceeds through an S N 2 reaction with secondary alcohols and an S N 1 reaction, comprising a tight ion pair, with tertiary alcohols giving products with inversion of configuration at the stereogenic carbon in both cases. Ru-catalyzed ring-closing metathesis performed on the diallylated aromatic amines yields the pyrrolines substituted in the beta-position in excellent yields. In Chapter 3, the direct intramolecular substitution of non-derivatized alcohols has been developed using Fe OTf 3 as catalyst. An atom-efficient route to pyrroles substituted in the beta-position has been achieved in four high yielding steps by a combination of Pd, Ru, and Fe catalysis with only water and ethene as side-products. Enkel sökning Avancerad sökning - Forskningspublikationer Avancerad sökning - Studentuppsatser Statistik. In a second step, unsymmetrical diallylated aromatic amines are generated from the reaction of a second allylic alcohol with high selectivity in moderate to good yields by control of the reaction temperature. The hydroxyl group of enantioenriched benzyl, propargyl, allyl, and alkyl alcohols has been intramolecularly displaced by uncharged O-, N-, and S-centered nucleophiles to yield enantioenriched tetrahydrofuran, pyrrolidine, and tetrahydrothiophene derivatives with phosphinic acid catalysis. The five-membered heterocyclic products are generated in good to excellent yields, with high degree of chirality transfer, and water as the only side-product. Furthermore, phosphinic acid does not promote S N 1 reactivity. The synthetic route includes a Pd-catalyzed monoallylation step of amines with substituted allylic alcohols that proceeds to yield the monoallylated products in moderate to excellent yields. The first part of the thesis Chapter 2 describes nucleophilic allylation of amines with allylic alcohols, using a palladium catalyst to generate unsymmetrical diallylated amines. Computational studies support a bifunctional role of the phosphinic acid in which activations of both nucleofuge and nucleophile occur in a bridging S N 2-type transition state. This reaction will open up new atom efficient techniques that enable alcohols to be used as nucleofuges in substitution reactions in the future. Racemization experiments show that phosphinic acid does not promote S N 1 reactivity. Experimental studies showed that phosphinic acid does not promote S N 1 reactivity. Enkel sökning Avancerad sökning - Forskningspublikationer Avancerad sökning - Studentuppsatser Statistik. anon su

Anon su Video

LE PREPARO EL MEJOR CUMPLEAÑOS DE SU VIDA *no creeran lo que pasa* ripl2016.eu?pid=diva Anon Bunrit, Christian Dahlstrand, Sandra K. Olsson, Pemikar Srifa, Genping Huang, Andreas . Bunrit, Anon. Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi. Stockholm University. (Joseph Samec). Su.G., •. — , hrarlill laicas: Gustavos, Comoedia, s. historia Gustav! regis. Anon. Cent. II. Dealt skrift asyftas förmodligen af Stent eck p. 7: "Libelle in. The thesis is divided into two parts, describing three different catalytic systems. Density functional theory calculations corroborate a reaction pathway where the phosphinic acid operates as a bifunctional catalyst in the intramolecular substitution reaction. The reaction swedish handjob general and gives pyrroles japanese hot massage in free gams sex beta-position with linear and branched alkyl, benzyl, or aryl groups in overall good yields. At the time of the doctoral defense, the following papers were unpublished and had a status as follows: The hydroxyl groups of aryl, allyl, propargyl, and alkyl alcohols were substituted by O - N - and S -centered nucleophiles to generate five- and six-membered heterocycles in good to excellent yields with high enantiospecificities. In a second step, unsymmetrical diallylated single women in mobile al amines are generated from the reaction anon su a second allylic alcohol with high selectivity in moderate to good yields by control of the reaction temperature. anon su

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