Sökning: "aziridine"

Visar resultat 1 - 5 av 10 avhandlingar innehållade ordet aziridine.

  1. 1. Radical Cyclization Approaches to Pyrrolidines

    Författare :Magnus Beşev; Troels Skrydstrup; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; Radical cyclization; diastereselectivity; pyrrolidine; pyrroline; thiazoline; aziridine; Organisk kemi; Organic chemistry; Organisk kemi; organisk kemi; Organic Chemistry;

    Sammanfattning : Five-membered rings are readily prepared by 5-exo-trig radical cyclization. This thesis is concerned with novel methodology for pyrrolidine synthesis. We have synthesised selenium containing radical precursors from aziridines and α-phenylseleno ketones, and cyclized them to 2,4- and 3,4-disubstituted pyrrolidines. LÄS MER

  3. 2. C2- and C3-symmetric ligands via ring-opening of aziridines

    Författare :Fredrik Lake; KTH; []
    Nyckelord :asymmetric catalysis; aziridine; benzaldehyde; diethylzinc; enantionselective; ligand; proazaphosphatrane; ring-opening; sulfonamide; symmetry; titanium; nicronium;

    Sammanfattning : This thesis deals with the design and synthesis of chiralenantiopure nitrogencontaining ligands and the use of theseligands in asymmetric catalysis. A modular synthetic approachto enantiopure nitrogen-containing ligands was developed. Thesynthetic method is based on the ring-opening of activatedchiral aziridines by nitrogen nucleophiles. LÄS MER

  4. 3. Stereoselective Nucleophilic Additions to Aldehydes and Synthesis of α-Amino-β- Hydroxy-Esters

    Författare :Jakob Danielsson; Peter Somfai; Hans Adolfsson; Tobias Rein; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asymmetric induction; stereochemical models; Mukaiyama; polar Felkin-Anh; Cornforth-Evans; 1; 3-dipole; aziridine; cycloaddition; amino alcohol; carbonylation; Heck reaction; quaternary stereocenter;

    Sammanfattning : This thesis deals with the development of new reaction methodology as well as stereochemical investigations. The first part concerns the investigation of 1,2- and merged 1,2- and 1,3- asymmetric induction in Mukaiyama aldol additions to α-heteroatom and α,β- heteroatom substituted aldehydes respectively. LÄS MER

  5. 4. The synthesis of chiral bidentate (N,N), (N,P) and (N,O) ligands and their use in metal-mediated asymmetric carbon-carbon bond formation

    Författare :Fredrik Johansson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Chemistry; Kemi; organisk kemi; Organic Chemistry;

    Sammanfattning : This thesis covers three projects based on the metal-mediated formation of new chiral centers in the prescence of chiral ligands. The first project, involving (N,N)- ligands, concerns the synthesis of some (C2-symmetric bis(aziridine) ligands and the use of these in the addition of organolithium reagents to N-aryl protected imines leading to enantioselectivities of up to 89%. LÄS MER

  7. 5. Synthetic studies on the natural products Zoanthamine and Balanol

    Författare :Lars Tedenborg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Chemistry; Kemi; organisk kemi; Organic Chemistry;

    Sammanfattning : Three main projects are described in this thesis. In the first, a stereocontrolled route tothe marine alkaloid Zoanthamine was studied. A convergent approach based on thechiral starting materials (S)-Perillyl alcohol and (R)-4,5-Dihydro-5-hydroxymethyl-2(3H)-furanone was developed. LÄS MER