Avancerad sökning

Visar resultat 1 - 5 av 35 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Iridium Catalysed Asymmetric Hydrogenation of Pyridines

   Författare :Alban Cadu; Pher G. Andersson; Hans Adolfsson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hydrogenation; pyridine; catalytic; Iridium; Organisk kemi; Organic Chemistry;

   Sammanfattning : This thesis presents the hydrogenation of substituted pyridines using N,P-ligated iridium catalystsin homogeneous media. These iridium catalysts were developed within this research group in thepast decade. This method of hydrogenation is highly stereoselective, and in several cases good to excellent ees were obtained. LÄS MER

3. 2. Asymmetric Hydrogenations using N, P - Ligated Iridium Complexes

   Författare :Alexander Paptchikhine; Pher G. Andersson; Karl Anker Jørgensen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; asymmetric hydrogenation; iridium; birch; boronates; fluorine;

   Sammanfattning : The research described in this thesis focuses on the catalytic asymmetric hydrogenation of prochiral olefins using N, P – chelated iridium catalysts. This catalytic system is tolerant to a wide range of substrates and performs better than the well-known ruthenium- and rhodium-catalytic systems for substrates devoid of coordinating groups in proximity of the olefin. LÄS MER

4. 3. Enantio- and Regioselective Iridium-Catalyzed Hydrogenation of Olefins : From Development to Total Synthesis

   Författare :Cristiana Margarita; Pher Andersson; Xavier Verdaguer; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asymmetric hydrogenation; Iridium; Regioselectivity; Kinetic resolution; Total synthesis; organisk kemi; Organic Chemistry;

   Sammanfattning : The work presented in this thesis concerns the iridium-catalyzed asymmetric hydrogenation of cyclic olefins and allylic alcohols for the preparation of useful chiral intermediates with various substitution patterns. The strategy provides stereocontrol for both non-functionalized as well as functionalized substrates and aims to be implemented in the stereoselective preparation of chiral building blocks having more than one stereocenter. LÄS MER

5. 4. Hydrogenation, Transfer Hydrogenation and Hydrogen Transfer Reactions Catalyzed by Iridium Complexes

   Författare :Xu Quan; Pher Andersson; Jonathan Williams; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Iridium catalyst; carbene; N; P - ligand; asymmetric hydrogenation; transfer hydrogenation; hydrogen transfer reaction; alkylation; olefin; ketone; amide; organisk kemi; Organic Chemistry;

   Sammanfattning : The work described in this thesis is focused on the development of new bidentate iridium complexes and their applications in the asymmetric reduction of olefins, ketones and imines. Three new types of iridium complexes were synthesized, which included pyridine derived chiral N,P-iridium complexes, achiral NHC complexes and chiral NHC-phosphine complexes. LÄS MER

7. 5. N-Heterocyclic Carbene-Phosphine Iridium Catalyzed Alkylation Reactions and Asymmetric Hydrogenation of Ketones

   Författare :Sutthichat Kerdphon; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; C-C coupling reactions; hydrogen transfer; iridium; ketones; methylation;

   Sammanfattning : This thesis is focused on hydrogen transfer reactions using N-heterocyclic carbenephosphine iridium catalysts and is divided in two parts. The first part describes the use of achiral N-heterocyclic carbene-phosphine iridium complexes catalyzing the methylation of ketones and alkylation of amides using alcohols as the electrophile. LÄS MER