Chiral cyclic alpha azido ketones are very important compounds in organic chemistry. Because, the reduced forms of them are amino alcohols and these amino alcohols are interesting compounds for their biological activities. They have some pharmaceutical activities such as: potassium channel open up properties, treatment of central nervous system, antihypertensive properties, the agent of dopamin receptor activator, hypolipemic agent and dopamine agonist. These types of compounds have highly acidic alpha-protons, and many kinds of reactions can be performed with them. In this study, mainly, selective protonation of racemic compounds was performed with a new practical method and there are not so many examples related to deracemization in the literature. Alpha-azido derivatives of tetralone, indanone, chromanone, and thiochromanone structures are chosen as starting materials because of their importance for biological activities arising from their cyclic structures. Firstly, these &alpha / -azido compounds were synthesized according to literature. The acidic alpha-protons do not require strong bases. Their enantioselective deracemization and deracemization processes were screened by using Cinchona derivatives as organocatalysts. This screening process was monitored by chiral HPLC columns. The parameters such as catalyst loading, solvent, temperature, reaction time and additives were optimized to obtain high enantioselectivities up to 98%. In addition to deracemization reactions, Michael addition reactions were also performed by starting from &alpha / -azido chromanones. In these reactions different type of urea catalyst was used to activate the electrophilic part of trans-&beta / -nitrostyrene compound. Again by controlling the temperature, time and catalyst loading, two diastereomers were formed and the screening process was monitored by chiral HPLC columns again. The Michael products were obtained in up to 94% ee and 75% yield.

Palladium-catalyzed reactions have become one of the most important tools in modern organic chemistry due to its ability to catalyze the formation of new carbon-carbon bonds. The aim of the work presented in this thesis was to develop new palladium(II)-catalyzed addition reactions. In this work, cyanamides were investigated as a new substrate to give aryl amidines as products. The first protocol developed employed aryltrifluoroborates as the aryl partner, and the insertion of the aryl group into un-, mono-, and di-substituted cyanamides was successful for a wide variety of aryltrifluoroborates. An alternative method of generating the necessary intermediate for insertion into the cyanamide is the decarboxylative formation of aryl-palladium from aryl carboxylic acids. A protocol was developed for this reaction, but was unfortunately limited to a small number of ortho-substituted electron-rich aryl carboxylic acids. The mechanism was investigated by the means of DFT calculations and ESI-MS studies, and the rate-determining step was suggested to be the 1,2-carbopalladation based upon those results. A translation of the batch protocol to continuous-flow conditions was also demonstrated. The ideal method of generating the aryl-palladium species is by C-H bond activation, and this approach was demonstrated with indoles, giving a variety of 3-amidinoindoles as products. The mechanism was investigated by DFT calculations and a plausible catalytic cycle was proposed. A continuous-flow application of a desulfitative palladium(II)-catalyzed addition to nitriles to give ketones was developed. In addition, different reactor materials were evaluated in the microwave heated reactor cavity. Thus the reaction was shown to proceed with microwave heating in a borosilicate glass and an aluminum oxide reactor, and also in conditions mimicking conventional heating in a silicon carbide reactor. Finally, a protocol was developed for the convenient synthesis of sodium aryl sulfinates from Grignard and lithium reagents using a solid sulfur dioxide source as a safe alternative to the gas. The products of this protocol can be used as aryl-palladium precursors by a desulfitative process.

Over the last 20 years, asymmetric synthesis has seen considerable progress, particularly in the field of catalysis. In addition to enzyme catalysis and transition metal catalysis, organocatalysis, catalysis using small organic molecules also plays an important role in the asymmetric synthesis. Chiral organocatalysts allow the preparation of structurally interesting and optically pure molecules via various activation modes. This work is focused on the use of organocatalysis based on the formation of hydrogen bonds in organic synthesis. Our study was devoted to the enantioselective organocatalytic reactions of ketimines leading to the formation of chiral vicinal centers. The first part deals with the organocatalytic enantioselective addition reaction of α- fluoro(phenylsulfonyl)methanes to ketimines derived from isatin. The reaction utilizes catalysis of a commercially available quinoline alkaloid cinchonine. A series of enantiomerically pure compounds were prepared containing two neighboring stereocenters in good yields of up to 97%, with diastereoselectivity up to 6: 1 dr and with enantiomeric excesses of 70-98% ee. In most cases pure diastereomers were obtained. In the second part of the work a method of enantioselective orgnocatalytic synthesis of bis-spirocompounds containing two neighboring...