Sökning: "Organic acids."

Visar resultat 1 - 5 av 364 avhandlingar innehållade orden Organic acids..

1. 1. New Methodologies in Organic Chemistry: Applications to the Synthesis of α-Amino Acids and Natural Products

   Författare :Sebastian Hirner; Peter Somfai; Varinder Aggarwal; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic synthesis; 2-Vinylaziridines; 3-Pyrrolines; Ringexpansion; Rearrangement; Anisomycin; Total synthesis; α-Amino acids; Arylglycines; Weinreb amides; α-Arylation; Grignard reagents; Umpolung; Organic chemistry; Organisk kemi;

   Sammanfattning : This thesis deals with the development and application of new synthetic methodology in organic chemistry. The first part describes the development of a new protocol for the synthesis of 3-pyrrolines by means of a microwave-assisted ring-expansion reaction of 2-vinylaziridines. LÄS MER

3. 2. Diaryliodonium Salts : Development of Synthetic Methodologies and α-Arylation of Enolates

   Författare :Marcin Bielawski; Berit Olofsson; Antonio Togni; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hypervalent Iodine Compounds; One-Pot Synthesis; Regiospecific Synthesis; Aromatic Substitution; Aryl Iodides; Arenes; Boronic Acids; Heteroaromatics; Arylations; Reaction Mechanisms; Density Functional Calculations; Large Scale Synthesis; Organic synthesis; Organisk syntes; organisk kemi; Organic Chemistry;

   Sammanfattning : This thesis describes novel reaction protocols for the synthesis of diaryliodonium salts and also provides an insight to the mechanism of α-arylation of carbonyl compounds with diaryliodonium salts.  The first chapter gives a general introduction to the field of hypervalent iodine chemistry, mainly focusing on recent developments and applications of diaryliodonium salts. LÄS MER

4. 3. Selective transfer hydrogenations : Catalyst development and mechanistic investigations

   Författare :Jenny Wettergren; Hans Adolfsson; Serafino Gladiali; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; asymmetric catalysis; transfer hydrogenation; transition metal; amino acids; amino alcohols; Organic chemistry; Organisk kemi; Organic Chemistry; organisk kemi;

   Sammanfattning : By generating a library of amino acid-based ligands, pseudo-dipeptides, and combining them with transition metals, we have created selective and efficient ruthenium and rhodium catalysts for the asymmetric transfer hydrogenation of ketones. The ruthenium-catalyzed reaction was studied in detail, and we found that alkali metals play a crucial role for the reactivity and selectivity of the reaction. LÄS MER

5. 4. New methods and reagents for small scale synthesis of phosphor organic compounds with focus on the phosphonic acids and their analogues

   Författare :Rikard Wärme; Dan Johnels; Jacek Stawinski; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; micro scale; phosphorus oxyacids; solid phase; chlorination; fluorination; radiolabelling; Organic synthesis; Organisk syntes; organisk kemi; Organic Chemistry;

   Sammanfattning : The development of a synthetic method of radiolabelled methylphosphono-fluoridates on a milligram scale is presented. The aim of this method is, besides affording high yield, to choose reaction pathways and reagents so that handling and transfer of labelled toxic substances is minimised, thereby reducing the risk of exposure as much as possible. LÄS MER

7. 5. Synthesis of aromatic bis- and tris(amino acids) and chiral dendrimers

   Författare :Andreas Ritzén; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organisk kemi; Organic chemistry; HWE reaction; asymmetric hydrogenation; Heck reaction; Amino acids; chiral dendrimers;

   Sammanfattning : A number of protected aromatic bis- and tris(amino acids) have been synthesised by catalytic asymmetric hydrogenation of the corresponding didehydroamino acid derivatives. The didehydroamino acid derivatives were prepared either by a Heck coupling of a 2-amidoacrylate with an aryl dihalide, or by Horner-Wadsworth-Emmons olefination of aromatic aldehydes with phosphonylglycine reagents. LÄS MER