Aryl cyclopropyl ketones have often been employed as diagnostic probes for single electron transfer (SET) in organic chemical reactions. The implicit assumption in such studies is that the formation of rearranged product(s) can be ascribed to the intermediacy of a ketyl anion. Through a detailed examination of the decay of electrolytically generated aryl cyclopropyl] ketyl anions, we have shown that the assumptions made in the use of these substrates as SET probes are not necessarily valid. Using derivative cyclic and linear sweep voltammetry it was discovered that the ketyl anions of alkyl- and unsubstituted aryl cyclopropyl ketones (class I), including phenyl cyclopropyl ketone (28a), 1-benzoyl-2-methylcyclopropane (28b), 1-benzoyl-2,2-dimethylcyclopropane (28c), p-tolyl cyclopropyl ketone (28d), and 1-benzoyl-1-methylcyclopropane (28e), undergo a slow and reversible cyclopropyl carbinyl type rearrangement followed by dimerization of the ring-opened and ring-closed radical anions. The equilibrium constant for the reversible ring opening lies highly in favor of the ring closed form. For (28a^·⁻) in anhydrous N,N-dimethylformamide containing 0.5 M n-Bu₄NBF₄ at 23 °C, the equilibrium constant was estimated at K ≈ 4.6 x 10⁻⁸ with a maximum rate constant for ring opening and a minimum rate constant for ring closing at 2.0 s⁻¹ and 4.3 x 10⁷ s⁻¹ respectively; the rate constant for dimerization was placed at 8.4 x 10⁷ M⁻¹s⁻¹. Semiempirical molecular orbital calculations (AM1) complement the above observations. Similar results were obtained for all class I compounds. The ketyl anions of aryl cyclopropyl ketones with good radical stabilizing groups on the cyclopropane ring (class ID), including trans-1-benzoyl-2-phenylcyclopropane (66), and 1-benzoyl-2-vinylcyclopropane (76) undergo rapid unimolecular ring opening. The rate constants for opening of (66^·⁻) and (76^·⁻) are greater than 10³ s⁻¹ but probably less than 10⁷ s⁻¹ and 10⁵ s⁻¹ respectively. Based upon our findings, class I ketones are extremely unreliable probes for SET; class II ketones may prove to be useful SET probes, but since absolute rate constants for their rearrangement are not yet known, they should be used only with extreme caution. The implications of these results are discussed in light of utilizing aryl cyclopropyl ketones as probes for SET. / Ph. D.

In 1947, while working on the aromatic cyclodehydration of ketones to their corresponding substituted anthracenes, Vingiello (1a) attempted to prepare 9-cyclohexylanthracene using this method. It was evident in the cyclization of o-benzylcyelohexyl-phenone (I) that the hydrol (II) postulated as an intermediate could lose water in two ways, yielding two different compounds 9,10-dihydro-9-cyclohexenylanthracene (IV) and 9-cyclohexyl-anthracene (III). This is shown in Chart I. Since a carbon, hydrogen analysis gives the same result for both compounds it is obvious that some other method of identification is necessary. It is the purpose of this part of the investigation to attempt to identify the existing structure by ultra-violet absorption analysis, and formation of derivatives and also to attempt to prepare 9-cyclohexylanthracene by an unequivocal method. / Master of Science

In a recent study of cyclodehydrogenation reactions of potential carcinogenic or carcinolytic hydrocarbons Zajac pointed out that ring closure of 12-(3-methylphenyl)- benz[a]anthracene might take place at either of the two ortho positions or the phenyl ring. These positions are not equivalent with respect to the methyl group and ring closure might yield either 2-methyldibenzo[a,1]pyrene or 4-methyldibenzo[a,1]pyrene or both. The objectives of the present investigation are to study possibilities and methods to prepare 2-(2-naphthylmethyl)- 2'-chloro-5'-methylbenzophenone in a sufficient yield so that a study of the cyclization reaction under a variety of conditions can be made in order to prepare 2-methyldibenzo[a,l]pyrene. During the course of the investigation an improved synthetic route to prepare 2-bromonaphthalene was secured. Three methods utilizing Grignard reagents were approached in order to prepare 2-(2-naphthyl~ethyl)-2'halobenzophenones necessary for the study to obtain 2-(2-naphthylmethyl)-2'-chloro-5'-methylbenzophenone. The only successful preparative method for the above ketones was found to be the reaction between a Grignard reagent and an acid halide. This procedure was applied to the preparation of the following new ketones: 2-(2-naphthylmethyl)-2'-fluorobenzophenone, 2-(2-naphthylmethyl)- 2'-chlorobenzophenone, and 2-(2-naphthylmethyl)- 2'-chloro-5'-methylbenzophenone. Investigation of the sealed tube method revealed that the above ketones could be cyclized at 180° with a mixture of hydrobromic and acetic acids in seven hours. Under these conditions the new compounds 12-(2-fluorophenyl) benz[a]anthracene, 12-(2-chlorophenyl)benz[a]- anthracene, and 12-(2-chloro-5-methylphenyl)-7,12-dihydrobenzo[ a]anthracene were obtained. Further study showed that 12-(2-chloro-5-methylphenyl)-7,12-dihydro-benz[a]anthracene could be obtained in a much better yield when the above procedure was altered by using a mixture of hydriodic and acetic acids. In order to obtain 2-methyldibenzo[a,1]pyrene 12-(2-chloro-5-methylphenyl)-7,12-dihydrobenzo[a]anthracene was reacted with potassium hydroxide and quinoline. Although the results were not definite the qualitative tests and the ultraviolet and infrared spectra suggest an intermediate dihydro compound. The ultraviolet and infrared spectra of six new compounds were recorded. / Master of Science

Indiana University-Purdue University Indianapolis (IUPUI) / The modification of brucine derivatives as chiral ligands and the use of a multifaceted chiral ligand, brucine diol, under different reaction conditions to produce various optical isomers is described. In Chapter 1, the generation of a number of brucine derivatives is described. Taking the advantage of brucine-diol’s excellent molecular recognition capability for multiple organic functional groups, we focused on the synthetic modifications of brucine-diol and the synthesis of brucine N-oxide. We also produced various brucine derivatives with different functional moieties in good yields and selectivities. In Chapter 2, we described the investigation of brucine N-oxide catalyzed Morita-Baylis-Hillman (MBH) reaction of alkyl/aryl ketones. Brucine N-oxide was used as a nucleophilic organic catalyst in the MBH reaction of alkyl vinyl ketone. In addition, asymmetric MBH reactions of alkyl vinyl ketones with aldehydes were investigated using a dual catalysis of brucine N-oxide and proline. In this dual catalyst system, proline was found to form iminium intermediates with electron-deficient aryl aldehydes, while the N-oxide activated vinyl ketones provided enolates through the conjugate addition. Our dual catalysis approach also allowed the development of MBH reaction of aryl vinyl ketones. In Chapter 3, brucine diol-copper complex catalyzed asymmetric conjugate addition of glycine (ket)imines to nitroalkenes is discussed. Stereodivergent catalytic asymmetric conjugate reactions for glycine (ket)imines with nitroalkenes were achieved using various chiral catalysts derived from a single chiral source, brucine diol. Both syn- and anti-conjugate addition products were obtained with high diastereoselectivity and enantioselectivity. In Chapter 4, enantiodivergent production of endo-pyrrolidines from glycine (ket)imines using brucine diol-copper complex is described. The [3+2] cycloaddition reaction of glycine imines and activated alkenes was performed to produce endo-pyrrolidines. The reversal of enantioselectivity was observed for endo-pyrrolidines between concerted and stepwise reaction pathways. The three new brucine derivatives produced in this study would potentially work as organocatalysts and chiral ligands with metal ion in asymmetric synthesis. The brucine diol-metal complex catalyzed reactions laid a good foundation for catalytic asymmetric reactions, where a single chiral source was used to control the absolute and the relative stereochemical outcomes of reactions. Understanding the molecular-level interactions between catalyst and substrates will provide insightful mechanistic details for the stereodivergent approaches in asymmetric catalysis.