Sökning: "Lewis acid"

Visar resultat 6 - 10 av 69 avhandlingar innehållade orden Lewis acid.

1. 6. Lewis Acid Mediated Alkylation and Diels-Alder Reactions of 2H-Azirines

   Författare :Erik Risberg; KTH; []
   Nyckelord :2H-azirines; Lewis acid activation; chiral ligandsorganolithium reagentsDiels-Alder reactions; DFT-calculations;

   Sammanfattning : This thesis describes the use of 2H-azirines as reactivesubstrates in Lewis acid catalysed nucleophilic additions andin the Diels-Alder reaction.A number of carbon nucleophiles have been added to aseries of 2H-azirines in the presence and absence ofBF3·Et2O. LÄS MER

3. 7. Efficient Synthesis and Analysis of Chiral Cyanohydrins

   Författare :Stina Lundgren; Christina Moberg; Ben Feringa; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; asymmetric catalysis; cyanohydrins; microreactor; polymersupported catalyst; ketonitriles; titanium; lanthanide; Lewis acid; Lewis base; Organic chemistry; Organisk kemi;

   Sammanfattning : This thesis deals with the development of new methods for efficient synthesis and analysis in asymmetric catalysis. It focuses on the preparation of chiral cyanohydrins by enantioselective addition of cyanide to prochiral aldehydes. LÄS MER

4. 8. Development and Studies of the Processes Involved in Minor Enantiomer Recycling

   Författare :Anna Laurell Nash; Christina Moberg; Karl Anker Jørgensen; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; asymmetric catalysis; biocatalysis; cyanohydrins; dual activation; Lewis acid; Lewis base; minor enantiomer recycling; recycling; titanium; Kemi; Chemistry;

   Sammanfattning : This thesis describes the development and rationalization of processes involved in a new methodology developed in our group, minor enantiomer recycling.The first part of the thesis addresses mechanistic studies of one of the reactions involved in minor enantiomer recycling, dual Lewis acid-Lewis base catalyzed acetylcyanation of aldehydes. LÄS MER

5. 9. Ash chemistry and fuel design focusing on combustion of phosphorus-rich biomass

   Författare :Nils Skoglund; Dan Boström; Rainer Backman; Franz Winter; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; phosphorus; biomass; combustion; ash chemistry; fuel design; ash transformation; phosphorus-rich; ash-forming elements; fuel fingerprint; ash transformation reactions; Lewis base; Lewis acid; oorganisk kemi; Inorganic Chemistry;

   Sammanfattning : Biomass is increasingly used as a feedstock in global energy production. This may present operational challenges in energy conversion processes which are related to the inorganic content of these biomasses. As a larger variety of biomass is used the need for a basic understanding of ash transformation reactions becomes increasingly important. LÄS MER

7. 10. New Methods for Chiral Cyanohydrin Synthesis

   Författare :Erica Wingstrand; Christina Moberg; Benjamin List; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; acyl cyanides; asymmetric synthesis; biocatalysis; cyanide; cyanohydrins; dual activation; enzymes; high-throughput screening; Lewis acid; Lewis base; metal catalysis; minor enantiomer recycling; salen; titanium; Chemistry; Kemi;

   Sammanfattning : This thesis deals with method development in asymmetric catalysis and specifically syntheses of enantioenriched O-functionalized cyanohydrins. The first part describes the development of a method for the synthesis of O‑alkoxycarbonylated and O-acylated cyanohydrins. LÄS MER