While hundreds of papers have been published on frustrated Lewis pairs (FLPs) – the combination of bulky Lewis acids and bases which cannot form adducts – few of these use aluminum-based Lewis acids. The research outlined in this thesis expands the small molecule activation chemistry of FLPs to include Al.Combinations of bulky phosphines and AlX3 (X = halide or C6F5) with CO2 leads to the rapid activation to form the complexes R3P(CO2)(AlX3)2 (R = otol, Mes). Subsequent treatment with ammonia borane (AB) results in the rapid reduction of the CO2 fragment to methanol after water quench. Subsequent reactivity studies have established that AB adducts of AlX3, which react with CO2, are key intermediates in this chemistry. Further studies with Mes3P(CO2)(AlX3)2 revealed that these can reduce exogenous CO2 to CO, along with the generation of Mes3P(C(OAlX2)2O)(AlX3) and [Mes3PX][AlX4]. Detailed experimental and theoretical mechanistic investigations outline a possible mechanism involving direct CO2 insertion into free AlX3, followed by nucleophilic attack by PMes3 resulting in the expulsion of CO. Reactions with olefins were also investigated. While addition products of the type R3P(CH2CH2)AlX3 could be obtained with ethylene, C–H bond activation occurred with bulkier olefins. The resulting allyl species underwent subsequent C–C bond forming reactions with other olefins or CO2. Hydrogen was also activated using PR3/AlX3 FLPs to form species of the general formula, [R3PH][(H)(AlX3)2] (X = I, C6F5). These were found to reduce unactivated olefins, generating the redistributed products [R3PH][AlX4] and RAlX2 (R = alkyl). Attempts to circumvent this redistribution and favour alkyl protonation, thus generating a catalytic hydrogenation catalyst, are also discussed. Finally, the activation of N2O was also examined. While addition products could be formed, unexpected aromatic or benzylic C–H bond activation chemistry occurred in the presence of excess Al. A radical reaction pathway is proposed

Three classes of bifunctional compounds related to frustrated Lewis pair chemistry were studied. The first class, alkynyl-linked phosphonium borates, was strategically synthesized and the corresponding neutral alkynyl-linked phosphine boranes generated in solution. They were reacted with THF, alkenes and alkynes to undergo either ring-opening or multiple bond addition reactions, giving rise to zwitterionic macrocycles. In two select alkynyl-linked phosphonium borates, thermolysis resulted in unique rearrangements transforming the phosphino- and boryl-substituted alkynyl moieties into C4 chains. The alkynyl-linked phosphine boranes were further demonstrated to coordinate as η3-BCC ligands in Ni(0) complexes. The rigid nature of the coordination was confirmed by dimerization without cleavage of the Ni–B interaction upon the addition of acetonitrile or carbon monoxide. Moreover, reactions with Al-, Zn- and B-based Lewis acids prompted hydride transfer within the alkynyl-linked phosphonium borate and interesting functional group transfer reactions. The second class of the bifunctional systems, a series of gem-substituted bis-boranes, was subjected to reactions with tBu3P and CO2. The O-linked bis-borane was shown to coordinate the phosphino-carboxylate moiety with one B, while the methylene-linked bis-boranes were demonstrated to chelate the carboxyl group. The third bifunctional system class, vinyl-group tethered boranes, was examined to elucidate the mechanism of the frustrated Lewis pair addition reaction to olefins. Using a bis(pentafluorophenyl)alkylborane, the close proximity of the olefinic protons and the ortho-fluorine nuclei were evident by both NOE measurements and DFT calculations. Moreover, its reactions with phosphine bases suggested that an initial interaction between the highly electrophilic borane and the olefinic fragment precedes such frustrated Lewis pair addition reaction. Furthermore, a bis(pentafluorophenyl)alkoxyborane was synthesized and reacted with P-, N-, C- and H-based nucleophiles, demonstrating the wide range of Lewis bases that can be applied in olefin addition reactions with complementary regioselectivity.

While hundreds of papers have been published on frustrated Lewis pairs (FLPs) – the combination of bulky Lewis acids and bases which cannot form adducts – few of these use aluminum-based Lewis acids. The research outlined in this thesis expands the small molecule activation chemistry of FLPs to include Al.Combinations of bulky phosphines and AlX3 (X = halide or C6F5) with CO2 leads to the rapid activation to form the complexes R3P(CO2)(AlX3)2 (R = otol, Mes). Subsequent treatment with ammonia borane (AB) results in the rapid reduction of the CO2 fragment to methanol after water quench. Subsequent reactivity studies have established that AB adducts of AlX3, which react with CO2, are key intermediates in this chemistry. Further studies with Mes3P(CO2)(AlX3)2 revealed that these can reduce exogenous CO2 to CO, along with the generation of Mes3P(C(OAlX2)2O)(AlX3) and [Mes3PX][AlX4]. Detailed experimental and theoretical mechanistic investigations outline a possible mechanism involving direct CO2 insertion into free AlX3, followed by nucleophilic attack by PMes3 resulting in the expulsion of CO. Reactions with olefins were also investigated. While addition products of the type R3P(CH2CH2)AlX3 could be obtained with ethylene, C–H bond activation occurred with bulkier olefins. The resulting allyl species underwent subsequent C–C bond forming reactions with other olefins or CO2. Hydrogen was also activated using PR3/AlX3 FLPs to form species of the general formula, [R3PH][(H)(AlX3)2] (X = I, C6F5). These were found to reduce unactivated olefins, generating the redistributed products [R3PH][AlX4] and RAlX2 (R = alkyl). Attempts to circumvent this redistribution and favour alkyl protonation, thus generating a catalytic hydrogenation catalyst, are also discussed. Finally, the activation of N2O was also examined. While addition products could be formed, unexpected aromatic or benzylic C–H bond activation chemistry occurred in the presence of excess Al. A radical reaction pathway is proposed

No description available.

A new method for the efficient synthesis of ferrocenylenones was developed. Acryloyl, methacryloyl, crotonyl, cinnamoyl, and &amp / #946 / -methylcrotonyl chlorides reacted with ferrocene in the presence of a Lewis acid (EtAlCl2 or EtAlCl2-Me3Al) to give the corrosponding ferrocenylenones (acryloyl, methacryloyl, crotonyl, cinnamoyl, and &amp / #946 / -methylcrotonylferrocenes) in good isolated yields. Using the Gabriel-Cromwell reaction, acryloyl and crotonoylferrocenes were converted to the novel ferrocenyl substituted aziridines with benzylamine, isopropylamine and furfurylamine. The aziridines were isolated in good to excellent yields.

No description available.

Thesis (Ph.D.)--University of North Carolina at Greensboro, 2007. / Title from PDF t.p. (viewed Mar. 3, 2008). Directed by Scott Romine; submitted to the Dept. of English. Includes bibliographical references (p. 203-214).

Thesis (D. Min.)--Abilene Christian University, 1996. / Includes abstract. Includes bibliographical references (leaves 221-229).

Thesis (M.A.)--Brigham Young University. Dept. of English, 2007. / Includes bibliographical references (p. 69-71).

Zugl.: Aachen, Techn. Hochsch. und Metz, Univ., Diss., 2006 u.d.T.: Salin, Sophie: Verflechtung nietzscheanischfreudianischer Motive mit dem Werk Gilles Deleuzes und Salin, Sophie: Cryptologie de l'inconscient