No description available.

The experimental results of the current work have two parts. First the synthesis, characterization, and spontaneous copolymerization of two highly electrophilic imines, tricyanomethanimine and methyl 3-aza-α, β-dicyanoacrylate. 1,1-Dichloro-2,2-dicyanoethylene or methyl 3,3-dichloro-2-cyanoacrylate reacted with excess sodium azide to give the corresponding diazides, which smoothly underwent thermolysis in solution to give a solution of the novel tricyanomethanimine or methyl 3-aza-α, β-dicyano-acrylate. Attempted isolation gave only oligomers, but reactions using solution of these imines succeeded. Cyclopentadiene and 2,3-dimethyl-1,3-butadiene afforded hetero Diels-Alder reactions. N,N-Dimethylaniline with tricyanomethanimine gave a p-substituted derivative, but with methyl 3-aza-α, β-dicyanoacrylate only a charge transfer complex was formed. Imines - p-methoxystyrene copolymers were obtained. These imines are as reactive as TCNE, but in contrast can also polymerize. Second, a new unsymmetrically substituted quinodimethane was synthesized, characterized, and copolymerized with electron donating monomers. Oxidation of the 1-cyano-1-phenylmethylene-4-cyano-4-ethoxycarbonylmethylene with MnO₂ gave mostly poly-7,8-dicyano-7-ethoxycarbonyl-8-phenylquinodimethane (DCEPQ), but depolymerization by sublimation yielded 45% of DCEPQ. This compound was a mixture of cis and trans isomers. It was homopolymerized by anionic initiation. High molecular weight copolymers of DCEPQ-styrene, DCEPQ-p-methylstyrene and DCEPQ-p-methoxystyrene(p-MeOSt) were formed spontaneously in 1,2-dichloroethane. All polymerizations occurred by a radical mechanism. High molecular weight polymers formed at low conversion. DCEPQ - p-MeOSt copolymerizations yielded alternating copolymers. From spontaneous polymerization of DCEPQ with NVC no copolymer was obtained. All of these polymerizations begin with a bond forming mechanism and propagate by polyaddition.

This thesis describes investigations into the catalysed syntheses of amines and imines using organoiridium and organorhodium complexes with N-donor ligands as the catalysts. These catalysed syntheses were achieved via hydroamination, hydrosilylation, and hydrogenation reactions, as well as tandem hydroamination/imine reduction reactions. An in situ catalysis study found that the most active catalysts for the hydroamination of 4-pentyn-1-amine (1) to give 2-methyl-1-pyrroline (4) were formed from a combination of catalyst components that resulted in an electron deficient metal centre, indicating that an alkyne binding mechanism was most likely. The kinetics of the hydroamination of 4-pentyn-1-amine (1), catalysed by the complexes [Rh(bim)(CO)2][BPh4] (7), [Ir(bim)(CO)2][BPh4] (8), [Rh(bpm)(CO)2][BPh4] (9),and [Ir(bpm)(CO)2][BPh4] (10) (bpm = bis(1-pyrazolyl)methane and bim = bis(Nmethylimidazol- 2-yl)methane) were modelled and compared. The nature of the metal centre was found to have the most influence on the rate of the product release step, while the nature of the N-donor ligand was found to have the most influence on the rate of the substrate binding step. The investigation of the catalysed hydroamination of the phenyl substituted alkynylamines 5-phenyl-4-pentyn-1-amine (2), 4-phenyl-3-butyn-1-amine (13) and 2- phenyl-4-pentyn-1-amine (34) revealed a difference in catalytic activity between the rhodium and iridium complexes depending on the alkyne substituent. A series of novel rhodium(I) complexes were synthesised: [RhClCO(Mes-DAD(Me))] (38), [RhClCO(Mes-BIAN)] (22), [Rh(COD)(Mes-BIAN)][BF4] (39), [Rh2(COD)2(bmimen)](BPh4)2 (40) and [Rh2(CO)4(bmimen)](BPh4)2 (41), where Mes- DAD(Me) = biacetylbis(2,4,6-trimethylphenylimine), Mes-BIAN = bis(2,4,6- trimethylphenylimino)acenapthene and bmimen = 1,2-bis[(1-methyl-2- imidazolyl)methylene-amino]ethane. The cationic complex 40 was found to be an active hydroamination catalyst, while the neutral complexes 38 and 22 were only active in the presence of the tetraphenylborate counterion. A range of imines was found to be efficiently reduced to their respective amines via hydrosilylation or hydrogenation using the iridium(I) complex [Ir(bpm)(CO)2][BPh4] (10) as catalyst. The hydrosilylation reaction was found to be significantly faster in a protic solvent (methanol), giving the desilylated amines without the need for a desilylation step. The mechanism of this reaction was proposed to involve a monohydride iridium(I) complex as a key intermediate. The tandem hydroamination/hydrosilylation of a series of alkynylamine substrates was achieved using the iridium complexes 8 and 10, in which the iridium complex catalyses the two mechanistically distinct reactions in the one-pot. Catalysed tandem hydroamination/hydrogenation reactions were also achieved, but were less facile.

This thesis describes investigations into the catalysed syntheses of amines and imines using organoiridium and organorhodium complexes with N-donor ligands as the catalysts. These catalysed syntheses were achieved via hydroamination, hydrosilylation, and hydrogenation reactions, as well as tandem hydroamination/imine reduction reactions. An in situ catalysis study found that the most active catalysts for the hydroamination of 4-pentyn-1-amine (1) to give 2-methyl-1-pyrroline (4) were formed from a combination of catalyst components that resulted in an electron deficient metal centre, indicating that an alkyne binding mechanism was most likely. The kinetics of the hydroamination of 4-pentyn-1-amine (1), catalysed by the complexes [Rh(bim)(CO)2][BPh4] (7), [Ir(bim)(CO)2][BPh4] (8), [Rh(bpm)(CO)2][BPh4] (9),and [Ir(bpm)(CO)2][BPh4] (10) (bpm = bis(1-pyrazolyl)methane and bim = bis(Nmethylimidazol- 2-yl)methane) were modelled and compared. The nature of the metal centre was found to have the most influence on the rate of the product release step, while the nature of the N-donor ligand was found to have the most influence on the rate of the substrate binding step. The investigation of the catalysed hydroamination of the phenyl substituted alkynylamines 5-phenyl-4-pentyn-1-amine (2), 4-phenyl-3-butyn-1-amine (13) and 2- phenyl-4-pentyn-1-amine (34) revealed a difference in catalytic activity between the rhodium and iridium complexes depending on the alkyne substituent. A series of novel rhodium(I) complexes were synthesised: [RhClCO(Mes-DAD(Me))] (38), [RhClCO(Mes-BIAN)] (22), [Rh(COD)(Mes-BIAN)][BF4] (39), [Rh2(COD)2(bmimen)](BPh4)2 (40) and [Rh2(CO)4(bmimen)](BPh4)2 (41), where Mes- DAD(Me) = biacetylbis(2,4,6-trimethylphenylimine), Mes-BIAN = bis(2,4,6- trimethylphenylimino)acenapthene and bmimen = 1,2-bis[(1-methyl-2- imidazolyl)methylene-amino]ethane. The cationic complex 40 was found to be an active hydroamination catalyst, while the neutral complexes 38 and 22 were only active in the presence of the tetraphenylborate counterion. A range of imines was found to be efficiently reduced to their respective amines via hydrosilylation or hydrogenation using the iridium(I) complex [Ir(bpm)(CO)2][BPh4] (10) as catalyst. The hydrosilylation reaction was found to be significantly faster in a protic solvent (methanol), giving the desilylated amines without the need for a desilylation step. The mechanism of this reaction was proposed to involve a monohydride iridium(I) complex as a key intermediate. The tandem hydroamination/hydrosilylation of a series of alkynylamine substrates was achieved using the iridium complexes 8 and 10, in which the iridium complex catalyses the two mechanistically distinct reactions in the one-pot. Catalysed tandem hydroamination/hydrogenation reactions were also achieved, but were less facile.

This thesis describes investigations into the catalysed syntheses of amines and imines using organoiridium and organorhodium complexes with N-donor ligands as the catalysts. These catalysed syntheses were achieved via hydroamination, hydrosilylation, and hydrogenation reactions, as well as tandem hydroamination/imine reduction reactions. An in situ catalysis study found that the most active catalysts for the hydroamination of 4-pentyn-1-amine (1) to give 2-methyl-1-pyrroline (4) were formed from a combination of catalyst components that resulted in an electron deficient metal centre, indicating that an alkyne binding mechanism was most likely. The kinetics of the hydroamination of 4-pentyn-1-amine (1), catalysed by the complexes [Rh(bim)(CO)2][BPh4] (7), [Ir(bim)(CO)2][BPh4] (8), [Rh(bpm)(CO)2][BPh4] (9),and [Ir(bpm)(CO)2][BPh4] (10) (bpm = bis(1-pyrazolyl)methane and bim = bis(Nmethylimidazol- 2-yl)methane) were modelled and compared. The nature of the metal centre was found to have the most influence on the rate of the product release step, while the nature of the N-donor ligand was found to have the most influence on the rate of the substrate binding step. The investigation of the catalysed hydroamination of the phenyl substituted alkynylamines 5-phenyl-4-pentyn-1-amine (2), 4-phenyl-3-butyn-1-amine (13) and 2- phenyl-4-pentyn-1-amine (34) revealed a difference in catalytic activity between the rhodium and iridium complexes depending on the alkyne substituent. A series of novel rhodium(I) complexes were synthesised: [RhClCO(Mes-DAD(Me))] (38), [RhClCO(Mes-BIAN)] (22), [Rh(COD)(Mes-BIAN)][BF4] (39), [Rh2(COD)2(bmimen)](BPh4)2 (40) and [Rh2(CO)4(bmimen)](BPh4)2 (41), where Mes- DAD(Me) = biacetylbis(2,4,6-trimethylphenylimine), Mes-BIAN = bis(2,4,6- trimethylphenylimino)acenapthene and bmimen = 1,2-bis[(1-methyl-2- imidazolyl)methylene-amino]ethane. The cationic complex 40 was found to be an active hydroamination catalyst, while the neutral complexes 38 and 22 were only active in the presence of the tetraphenylborate counterion. A range of imines was found to be efficiently reduced to their respective amines via hydrosilylation or hydrogenation using the iridium(I) complex [Ir(bpm)(CO)2][BPh4] (10) as catalyst. The hydrosilylation reaction was found to be significantly faster in a protic solvent (methanol), giving the desilylated amines without the need for a desilylation step. The mechanism of this reaction was proposed to involve a monohydride iridium(I) complex as a key intermediate. The tandem hydroamination/hydrosilylation of a series of alkynylamine substrates was achieved using the iridium complexes 8 and 10, in which the iridium complex catalyses the two mechanistically distinct reactions in the one-pot. Catalysed tandem hydroamination/hydrogenation reactions were also achieved, but were less facile.

No description available.

This thesis describes investigations into the catalysed syntheses of amines and imines using organoiridium and organorhodium complexes with N-donor ligands as the catalysts. These catalysed syntheses were achieved via hydroamination, hydrosilylation, and hydrogenation reactions, as well as tandem hydroamination/imine reduction reactions. An in situ catalysis study found that the most active catalysts for the hydroamination of 4-pentyn-1-amine (1) to give 2-methyl-1-pyrroline (4) were formed from a combination of catalyst components that resulted in an electron deficient metal centre, indicating that an alkyne binding mechanism was most likely. The kinetics of the hydroamination of 4-pentyn-1-amine (1), catalysed by the complexes [Rh(bim)(CO)2][BPh4] (7), [Ir(bim)(CO)2][BPh4] (8), [Rh(bpm)(CO)2][BPh4] (9),and [Ir(bpm)(CO)2][BPh4] (10) (bpm = bis(1-pyrazolyl)methane and bim = bis(Nmethylimidazol- 2-yl)methane) were modelled and compared. The nature of the metal centre was found to have the most influence on the rate of the product release step, while the nature of the N-donor ligand was found to have the most influence on the rate of the substrate binding step. The investigation of the catalysed hydroamination of the phenyl substituted alkynylamines 5-phenyl-4-pentyn-1-amine (2), 4-phenyl-3-butyn-1-amine (13) and 2- phenyl-4-pentyn-1-amine (34) revealed a difference in catalytic activity between the rhodium and iridium complexes depending on the alkyne substituent. A series of novel rhodium(I) complexes were synthesised: [RhClCO(Mes-DAD(Me))] (38), [RhClCO(Mes-BIAN)] (22), [Rh(COD)(Mes-BIAN)][BF4] (39), [Rh2(COD)2(bmimen)](BPh4)2 (40) and [Rh2(CO)4(bmimen)](BPh4)2 (41), where Mes- DAD(Me) = biacetylbis(2,4,6-trimethylphenylimine), Mes-BIAN = bis(2,4,6- trimethylphenylimino)acenapthene and bmimen = 1,2-bis[(1-methyl-2- imidazolyl)methylene-amino]ethane. The cationic complex 40 was found to be an active hydroamination catalyst, while the neutral complexes 38 and 22 were only active in the presence of the tetraphenylborate counterion. A range of imines was found to be efficiently reduced to their respective amines via hydrosilylation or hydrogenation using the iridium(I) complex [Ir(bpm)(CO)2][BPh4] (10) as catalyst. The hydrosilylation reaction was found to be significantly faster in a protic solvent (methanol), giving the desilylated amines without the need for a desilylation step. The mechanism of this reaction was proposed to involve a monohydride iridium(I) complex as a key intermediate. The tandem hydroamination/hydrosilylation of a series of alkynylamine substrates was achieved using the iridium complexes 8 and 10, in which the iridium complex catalyses the two mechanistically distinct reactions in the one-pot. Catalysed tandem hydroamination/hydrogenation reactions were also achieved, but were less facile.

This thesis describes investigations into the catalysed syntheses of amines and imines using organoiridium and organorhodium complexes with N-donor ligands as the catalysts. These catalysed syntheses were achieved via hydroamination, hydrosilylation, and hydrogenation reactions, as well as tandem hydroamination/imine reduction reactions. An in situ catalysis study found that the most active catalysts for the hydroamination of 4-pentyn-1-amine (1) to give 2-methyl-1-pyrroline (4) were formed from a combination of catalyst components that resulted in an electron deficient metal centre, indicating that an alkyne binding mechanism was most likely. The kinetics of the hydroamination of 4-pentyn-1-amine (1), catalysed by the complexes [Rh(bim)(CO)2][BPh4] (7), [Ir(bim)(CO)2][BPh4] (8), [Rh(bpm)(CO)2][BPh4] (9),and [Ir(bpm)(CO)2][BPh4] (10) (bpm = bis(1-pyrazolyl)methane and bim = bis(Nmethylimidazol- 2-yl)methane) were modelled and compared. The nature of the metal centre was found to have the most influence on the rate of the product release step, while the nature of the N-donor ligand was found to have the most influence on the rate of the substrate binding step. The investigation of the catalysed hydroamination of the phenyl substituted alkynylamines 5-phenyl-4-pentyn-1-amine (2), 4-phenyl-3-butyn-1-amine (13) and 2- phenyl-4-pentyn-1-amine (34) revealed a difference in catalytic activity between the rhodium and iridium complexes depending on the alkyne substituent. A series of novel rhodium(I) complexes were synthesised: [RhClCO(Mes-DAD(Me))] (38), [RhClCO(Mes-BIAN)] (22), [Rh(COD)(Mes-BIAN)][BF4] (39), [Rh2(COD)2(bmimen)](BPh4)2 (40) and [Rh2(CO)4(bmimen)](BPh4)2 (41), where Mes- DAD(Me) = biacetylbis(2,4,6-trimethylphenylimine), Mes-BIAN = bis(2,4,6- trimethylphenylimino)acenapthene and bmimen = 1,2-bis[(1-methyl-2- imidazolyl)methylene-amino]ethane. The cationic complex 40 was found to be an active hydroamination catalyst, while the neutral complexes 38 and 22 were only active in the presence of the tetraphenylborate counterion. A range of imines was found to be efficiently reduced to their respective amines via hydrosilylation or hydrogenation using the iridium(I) complex [Ir(bpm)(CO)2][BPh4] (10) as catalyst. The hydrosilylation reaction was found to be significantly faster in a protic solvent (methanol), giving the desilylated amines without the need for a desilylation step. The mechanism of this reaction was proposed to involve a monohydride iridium(I) complex as a key intermediate. The tandem hydroamination/hydrosilylation of a series of alkynylamine substrates was achieved using the iridium complexes 8 and 10, in which the iridium complex catalyses the two mechanistically distinct reactions in the one-pot. Catalysed tandem hydroamination/hydrogenation reactions were also achieved, but were less facile.

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed Nov. 1, 2007). Vita. Includes bibliographical references.

Chapter 1 is the introduction to the thesis. It contains an overview of amino acids and aminyl radicals. The amino acids section includes material on their synthesis through traditional methods and asymmetric syntheses, as well as the use of radical reactions in their formation. The aminyl radical section gives a description of the nature of the radical and then proceeds with general techniques for aminyl radical formation. A more detailed account of our own group's use of sulfenamides and imines in aminyl radical formation is ·covered and the chapter is ended with a look at the work of aminyl radicals in amino acid synthesis and my subsequent intentions in this area. The preparation and cyclisation of sulfenamide precursors derived from [alpha]-amino acids is discussed in chapter 2. Both the cyclisations of aminyl and urethanyl (introduction of benzyloxycarbonyl and tosyl protecting groups onto amine) radicals onto suitably placed alkenyl substituents were investigated. 5-Exo-trig cyclisation reactions successfully afforded the cyclic products in moderate yield with reasonable diastereoselectivity. The effects of the [alpha]-CO2R (where R = Me or tBu), the size of the amino acid side chain and placement of alkenyl substituent (N-substituted or sidechain containing alkene) are discussed. The use of imines as aminyl radical precursors is explored in chapter 3. [Alpha]-amino acids and aldehydes were condensed and the cyclisation products isolated. The formation of aminyl radicals by 5-exo-trig cyclisation and subsequent H-atom abstraction gave moderate to good yields of N-cyclopentyl substituted a-amino acids. Preparation of the aldehydes is discussed. Tandem cyclisations involving aspects of chapters 2 and 3 are looked at in chapter 4. The preparation of the unnatural a-amino acids required for tandem cyclisation and subsequent formation of the sulfenamide or imine is reported. 5-Exo, 6-exo cyclisation of the sulfenamide derivative gave the tandem product in low yield and with moderate diastereoselectivity. This was in contrast to the imine derived reaction which proved unsuccessful. The remaining chapters incorporate the detailing of experimental relevant to the discussion and the presentation of references quoted throughout the thesis.