Sökning: "asymmetric reductions of ketones"
Hittade 5 avhandlingar innehållade orden asymmetric reductions of ketones.
1. Catalytic Asymmetric Ketone and Alkene Reductions Using Transition Metal Complexes
Sammanfattning : This thesis contains seven papers dealing with iridium and ruthenium based catalytic asymmetric reductions, either of ketones into chiral alcohols, or olefins into chiral alkanes. The first part of the thesis describes how we have designed and evaluated new bicyclic ligands containing either N,S or N,N chelating atoms. LÄS MER
2. Asymmetric transfer hydrogenation of ketones : Catalyst development and mechanistic investigation
Sammanfattning : The development of ligands derived from natural amino acids for asymmetric transfer hydrogenation (ATH) of prochiral ketones is described herein. In the first part, reductions performed in alcoholic media are examined, where it is found that amino acid-derived hydroxamic acids and thioamides, respectively, are simple and versatile ligands that in combination with [RhCp*Cl2]2 efficiently catalyze this particular transformation. LÄS MER
3. Development and application of new chiral -amino alcohols in synthesis and catalysis : Use of 2-azanorboryl-3-methanols as common intermediates in synthesis and catalysis
Sammanfattning : The development and application of unnatural amino alcohols,prepared via hetero-Diels-Alder reactions,in synthesis and catalysis is described.The studies are concerned with the [i]scope of the hetero-Diels-Alder reaction and preparation of important intermediates in the synthesis of antiviral agents,[ii ]application of amino alcohols in the ruthenium transfer hydrogenation of ketones,[iii ]use of similar precursors in the in situ generation of oxazaborolidines for reduction of ketones,and [iv] development and application of new chiral auxiliaries for dialkylzinc additions to activated imines, respectively. LÄS MER
4. Synthesis and evaluation of bicyclic 1,3-diols (BODOLs) as ligands for asymmetric catalysis
Sammanfattning : Several ligands based upon 2-substituted bicyclic[2.2.2]octane-2,6-diols (BODOLs) were synthesized and evaluated in two catalytic reactions: I) the Ti(IV)-mediated catecholborane asymmetric reduction of prochiral ketones and II) as catalysts in the asymmetric addition of diethylzinc to aromatic aldehydes. LÄS MER
5. The influence of temperature on enzyme selectivity in organic media
Sammanfattning : The influence of different reaction parameters on enzyme selectivity was investigated. The reaction conditions studied were solvent dependence, water activity and reaction temperature. LÄS MER
