Search for dissertations about: "ring opening selective"

Showing result 1 - 5 of 8 swedish dissertations containing the words ring opening selective.

2. 1. Ring-opening catalysts for cetane improvement of diesel fuels

   Author : Ulf Nylén; Magali Boutonnet; Sven Järås; François Garin; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ring opening selective ; naphthenic structure; indan; light cycle oil LCO ; cetane; Pt-Ir catalyst; microemulsion; XPS; TPR; TEM; DRIFTS; sulphur analysis; GC-SCD; Chemical engineering; Kemiteknik;

   Abstract : The global oil refining industry with its present product distribution essentially shifted towards fuels such as gasoline and diesel will most likely hold the fort for considerable time. However, conditions are changing and refinery survival will very much depend on long-term planning, process and product flexibility and being at the frontiers of refining technology, a technology where catalysts play leading roles. READ MORE

4. 2. On the Ring-Opening Reaction of Thiophene-1,1-dioxides and the Intramolecular Diels-Alder Reaction of Azanona- and AzadecatrienesI

   Author : Anders Sebastian Tsirk; Centrum för analys och syntes; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; transition states; 3-21G * ; intramolecular Diels-Alder reactions; asymmetric induction; multivariate optimization; kinetic isotope effects; rearrangements; secondary amines; 1-dioxides; Ring-opening reaction; thiophene-1; stereoselectivity.; Organic chemistry; Organisk kemi;

   Abstract : Substituted thiophene-1,1-dioxides were synthesized and their ring-opening reactions with omega-unsaturated secondary amines were investigated; this led to a synthetic route to azatrienes and to the preparation of some polyhydroisoindoles and polyhydroisoquinolines via an intramolecular Diels-Alder reaction. By using 2-substituted pyrrolidines and piperidines various tetrahydrobenzo[f]indolizidines, benzo[b]quinolizidines, tetrahydrobenzo[a]indolizidines and tetrahydro[a]pyrrolizidines could be synthesized via the ring-opening of 3-bromo-2,5-dimmethylthiophene-1,1-dioxide and a subsequent intramolecular Diels-Alder reaction. READ MORE

5. 3. degradable electroactive polymers: Synthesis, Macromolecular architecture and scaffold design

   Author : Baolin Guo; Ann-Christine Albertsson; Patric Jannasch; KTH; []
   Keywords : Poly lactide ; poly ε-caprolactone ; ring-opening polymerization; carboxyl-capped aniline trimer; carboxyl-capped aniline pentamer; phenyl amino-capped aniline tetramer; coupling reaction; DCC DMAP system; degradability; electroactivity; conductivity; macromolecular architecture; chitosan; hydrogel; block copolymer; functionalization; oxidative coupling reaction; self-assembly; toxicity; tubular porous scaffold; neural tissue engineering.;

   Abstract : Electrically conducting polymers induce specific cellular responses at the molecular level. One of the crucial limitations of the use of conducting polymers in tissue engineering is their inability to degrade. READ MORE

6. 4. Radical Cyclization Approaches to Pyrrolidines

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

   Abstract : 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. READ MORE

7. 5. Nano- and Micro-sized Molecularly Imprinted Polymer Particles on Solid Surfaces

   Author : Tripta Kamra; Synkrotronljusfysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : Molecularly imprinted polymers (MIPs) are artificial receptors made by imprinting template molecules in a polymer matrix followed by their removal through washing to obtain a specific and selective template cavities. This property of the MIPs have made them a very efficient material for diverse applications such as chromatography, purification, drug sensing, etc. READ MORE