The first part of this thesis describes a synthetic strategythat provides all eight possible isomers of a given vic-aminoalcohol starting from vinylepoxides. The value of a generalroute is evident, as several isomers are needed ininvestigations of structure-activity relationships forpharmacologically active derivatives, and for optimizing theperformance of chiral ligands containing the amino alcoholmoiety. Vinylepoxides, obtained in high enantiomeric excess, werering-opened both with inversion and retention ofstereochemistry, delivering two diastereomeric amino alcoholswith high regio- and stereoselectivity. Via ring-closure toaziridines and subsequent regioselective ring-opening withsuitable oxygen nucleophiles, the two remaining amino alcoholswere selectively achieved. Within this study, two efficient protocols for theregioselective and stereospecific aminolysis of vinylepoxideshave been presented. Comparedto previous methods, theseprocedures use milder reaction conditions, shorter reactiontimes, generally give higher yields and are applicable to alarger set of substrates. Furthermore, the ring-closure ofvic-amino alcohols to the corresponding N-H vinylaziridines hasbeen investigated. Three routes have been found useful, whichone is preferred depends on substrate and scale. In the second part of the thesis, the synthetic strategy isapplied on the synthesis of Sphingosine and its regio- andstereoisomers. Moreover, a rapid way of determining relativeconfiguration of vic-amino alcohols is described, which shouldbe of substantial use when amino alcohols are formed bydiastereoselective reactions. amino alcohols, vinylepoxides, vinylaziridines, oxazolines,oxazolidinones, ring-opening, regioselective,diastereoselective, sphingosine, configuration, NMRspectroscopy.

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. The aziridines areconveniently prepared from amino alcohols. The structure oftheaziridine and of the nucleophile can be extensively varied andlibraries of ligands are easily prepared. The use of primaryamines affords C2-symmetric bis(sulfonamides), whereas the use ofammonia affords C3-symmetric tris(sulfonamides) that can beelaborated into the corresponding tetra-amines. The C2- and C3-symmetric ligands were used in the asymmetrictitaniummediated addition of diethylzinc to benzaldehyderesulting in modest enantioselection, 76% ee. A thoroughinvestigation of the reaction conditions revealed that theamount of Ti(OiPr)4has a decisive effect on the reaction rate and thestereochemical outcome of the reaction. The reaction timedecreased from about 90 hours to 15 minutes and theenantioselectivity changed from 26% of the (R)- enantiomer to72% of the (S)-enantiomer when the Ti(OiPr)4:benzaldehyde ratio was increased from 0.125:1 to1.48:1. Moreover, the titanium-mediated addition of diethylzincto benzaldehyde was studied in the presence of chiraladditives. The bis(sulfonamides) were also used in thecyclopropanation of cinnamyl alcohol. However, only lowenantioselection was observed, 27% ee. The C3-symmetric tetra-amines were reacted to formazaphosphatranes. These weak acids were only partiallydeprotonated by the strong base KOtBu to form the correspondingproazaphosphatranes. The unexpectedly strong basicity of theproazaphosphatranes was believed to be due to steric effects assuggested by DFT calculations. The tetra-amines and thesulfonamides were used for the preparation of metal complexesof Lewis acidic metals such as titanium(IV) andzirconium(IV). <b>Keywords:</b>asymmetric catalysis, aziridine, benzaldehyde,diethylzinc, enantioselective, ligand, proazaphosphatrane,ring-opening, sulfonamide, symmetry, titanium, zirconium

Telechelic polyesters have successfully been synthesized with lipase-catalyzed polymerization. The produced telechelics had a high degree of di­functionalization, high purity (requiring little or no workup) and controlled degree of polymerization. The syntheses were performed in one-pot one-step reaction systems. The use of protection/deprotection chemistry was not necessary, since the lipase selectivity was utilized in the syntheses. Two different types of lipase-catalyzed polymerizations were applied – ring-opening polymerization and polycondensation. In ring-opening polymerization telechelics were produced by a combination of initiation, α-functionalization, and linking through termination, w-func­tionalization. In polycondensation different types of end-cappers were used to synthesize telechelics. Several exampels of functional groups were used for end-functionalization - epoxide, methacrylate and tetraallyls. Enzyme kinetic schemes describing the different functionalization met­hods of polyesters are presented and discussed. Stoichiometry and different reaction conditions have been studied to understand the effects these functions have on the final structure of the synthesized telechelics. Polyesters are classified as biodegradable, and can also be synthesized from materials that can be extracted or fermented from renewable sources like plants. Lipase-catalysts have several beneficial attributes, like high selectivity, they are renewable and biodegradable, are non-toxic and metal-free and can operate under mild reaction conditions. The focus of this thesis has been on lipase-catalyzed syntheses and characterization of the produced telechelics, in addition some materials have been produced. Some uses of telechelics are surface modification, materials for block co-polymers, functional films and biomedical applications. / QC20100726

This work improved the radiosynthesis of a known M2 muscarinic receptor imaging agent, [18F]FP-TZTP, and subsequent syntheses and in vitro evaluation of several novel TZTP derivatives highlighted a lead compound which exhibited M4 potency and selectivity, the thioether fluoro-polyethyleneglycol, which was then adapted for radiolabelling (23% radiochemical yield (uncorrected), >99% radiochemical purity, reaction time of 37 minutes). The present study also seeked to utilize aziridines as intermediates in [18F]-radiolabelling chemistry for the facile radiosynthesis of [18F]-labelled beta-blockers. Novel [18F]-labelled amines were synthesized via ring-opening and deprotection to yield the [18F]-1-fluoro-2-propanamine moiety (85%) favourably over the regioisomer [18F]-2-fluoro-1-propanamine (15%). Subsequent attempts to use these amine synthons in the synthesis of the beta-blocker [18F]Exaprolol resulted in poor radiochemical yields (1-3%). The chemistry of aziridine ring-opening with 19F-fluoride sources was thoroughly explored in order to understand the fundamentals of this chemistry, and the 1-fluoro-2-propanamine moiety was characterized by X-ray crystallography and NMR spectroscopy.

A synthetic approach to produce lysergic acid by virtue of an asymmetric ring opening (ARO) of symmetrical 3,6-disubstituted-7,10-hydroxymethyl bridgehead substituted oxabicycles is described. The use of a Rhodium(I)/JosiPhos(R,S) catalyst system to effect an ARO using an amine nucleophile furnishes an enantiopure tetrahydronapthalene intermediate with the amine conveniently installed at the 6 position as in lysergic acid, with appropriate stereochemistry; further which, two subsequent annulations are necessary to form the fused 3,5-substituted indole and tetrahydropyridine to complete the synthesis. Progress of this work is described herein along with future directions. The second chapter in this thesis describes the modular and stereoselective synthesis of tetrasubstituted helical alkenes via a palladium-catalyzed domino reaction under Catellani conditions. These helical alkenes possess potentially interesting photochemical properties as molecular motors / switches, and can be applicable in the materials sciences as molecular machines.

A synthetic approach to produce lysergic acid by virtue of an asymmetric ring opening (ARO) of symmetrical 3,6-disubstituted-7,10-hydroxymethyl bridgehead substituted oxabicycles is described. The use of a Rhodium(I)/JosiPhos(R,S) catalyst system to effect an ARO using an amine nucleophile furnishes an enantiopure tetrahydronapthalene intermediate with the amine conveniently installed at the 6 position as in lysergic acid, with appropriate stereochemistry; further which, two subsequent annulations are necessary to form the fused 3,5-substituted indole and tetrahydropyridine to complete the synthesis. Progress of this work is described herein along with future directions. The second chapter in this thesis describes the modular and stereoselective synthesis of tetrasubstituted helical alkenes via a palladium-catalyzed domino reaction under Catellani conditions. These helical alkenes possess potentially interesting photochemical properties as molecular motors / switches, and can be applicable in the materials sciences as molecular machines.

This work improved the radiosynthesis of a known M2 muscarinic receptor imaging agent, [18F]FP-TZTP, and subsequent syntheses and in vitro evaluation of several novel TZTP derivatives highlighted a lead compound which exhibited M4 potency and selectivity, the thioether fluoro-polyethyleneglycol, which was then adapted for radiolabelling (23% radiochemical yield (uncorrected), >99% radiochemical purity, reaction time of 37 minutes). The present study also seeked to utilize aziridines as intermediates in [18F]-radiolabelling chemistry for the facile radiosynthesis of [18F]-labelled beta-blockers. Novel [18F]-labelled amines were synthesized via ring-opening and deprotection to yield the [18F]-1-fluoro-2-propanamine moiety (85%) favourably over the regioisomer [18F]-2-fluoro-1-propanamine (15%). Subsequent attempts to use these amine synthons in the synthesis of the beta-blocker [18F]Exaprolol resulted in poor radiochemical yields (1-3%). The chemistry of aziridine ring-opening with 19F-fluoride sources was thoroughly explored in order to understand the fundamentals of this chemistry, and the 1-fluoro-2-propanamine moiety was characterized by X-ray crystallography and NMR spectroscopy.

This dissertation describes the synthesis of molecular machines designed to operate on surfaces (nanocars) or in the solution phase (nanosubmarines), and the study of their diffusion using fluorescence techniques. The design of these molecular machines is aimed to facilitate monitoring of their movement and incorporation of a source of energy for propulsion. To complement previous scanning tunneling microscopy studies of the translation of nanocars on surfaces, chapter 1 describes the synthesis of a family of fluorescently tagged nanocars. The nanocars were functionalized with a tetramethylrhodamine isothiocyanate (TRITC) fluorescent dye. Single-molecule fluorescence microscopy (SMFM) studies of one of these nanocars revealed that 25% of the nanocars moved on glass. The SMFM results also suggested that the dye hindered the mobility of the nanocars. Seeking to improve the mobility, chapter 2 presents the synthesis of a new set of fluorescent nanocars, featuring a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dye embedded in their axles. The mobility of these inherently fluorescent nanocars on glass was nearly double than that of their TRITC-tagged predecessors. Their diffusion was also studied on reactive-ion-etched glass, and amino-functionalized glass. The results showed that the mobility is affected by the substrate. To equip the nanocars with an energy input for propulsion, two nanocars functionalized with an olefin metathesis catalyst were synthesized, as described in chapter 3. The catalytic activity of these nanocars toward ring-opening metathesis polymerization (ROMP) in solution was similar to that of their parent catalysts. As an alternative approach to investigate if chemical propulsion through a ROMP process can be achieved at the molecular level, chapter 4 presents the synthesis of a fluorescent ROMP catalyst, termed a nanosubmarine, and the study of its diffusion using fluorescence correlation spectroscopy (FCS). FCS results showed an increase of 20 ± 7% in the diffusion constant of this nanosubmarine in presence of its fuel, cis,cis-1,5-cyclooctadiene. Overall, the work accomplished in this dissertation constitutes a step forward toward development of easily tracked and highly mobile nanocars, and paves the way for the synthesis of truly nanosized chemically propelled molecular machines that operate in the solution phase.

This thesis describes syntheses and characterization of star-like amphiphilic block copolymers consisting of poly(ethylene glycol) (PEG) as the hydrophilic block,polycarbonate as the hydrophobic block and an amine-containing dendrimer as the core molecule. The macromolecules were synthesized by either a convergent or adivergent approach that includes tandem click reactions and ring opening polymerizations (ROP) of methyl trimethyl carbonates (MTC) with differentfunctionalities. The ROP of MTC monomers was performed using organocatalysts that allow mild reaction condition and reasonable molecular weight distribution(PDI~1.3). These synthetic approaches provide the resultant polymers with three different conformations, which are; mikto-arm type, comb-block with short PEGbrushes, and linear block with long PEG chain. The star-like polymers that were synthesized were all water soluble and most of them formed nano aggregates inwater. Different morphologies were observed in AFM study depending on the polymer conformation. Interestingly, some of them had indications pointing towards alower critical solution temperature.

The novel chelating ligand, Me[NOON]H2 (N,N'-((ethane-1,2-diylbis(oxy))-bis(ethane-2,1-diyl))- bis(2,6-dimethylaniline)), have been synthesized successfully and characterized by NMR. The lithium complexes of the aryl diamide ligand have also been synthesized by n-BuLi react with neutral ligand, Me[NOON]H2. And the lithium complexes is a ether adduct according to the 1H NMR. The lithium complex, Me[NOON]Li2(OEt2) react with Ti(OiPr)4 and TiCl4(THF)2 to form the NOON titanium alkoxide and dichloride complexes respectively, and they have been characterized by 1H NMR and X-ray diffraction. These NOON titanium complexes are expected to be a catalyst for the ring opening polymerization of lactide or caprolactone in the future. The tantalum complexes of diphenolate phosphine ligands have been synthesized and characterized successfully by NMR, X-ray diffraction, and elemental analysis. The tantalum complexes, [tBuOPO]2TaX (X=Me, Et, H) is produced by the reaction of [tBuOPO]2TaCl with Grignard reagent (MeMgBr and EtMgCl) and superhydride(LiHBEt3). These tantalum complexes will be applied in dinitrogen activation in the future work.