The usefulness of imines and iminium salts in the convergent synthesis of alkaloids and their synthetic analogues is described. Thus the anion derived from [3,4-c]pyridin-3[1H]-one, by treatment with LDA (lithium diisopropylamide) or LHS, (lithium bis-trimethylsilylamide) reacts with 2-methyl-3, 4-dihydro- isoquinolinium salts yielding aza analogues of phthalideisoquinoline alkaloids. The condensation of the same anion with 3,4-dihydroisoquinolines has provided, in a single step, azaprotoberberines containing the benzo[a)pyrido[3,4-g]quinolizine structure found in a number of Alangium alkaloids. The reaction of methyllithium with oxoberberine as a means of introducing a methyl group C-8 is described. The resulting iminium salt was reduced to a mixture of racemic a- and B-8-methylcanadines. This reaction has been applied to the synthesis of the Alangium alkaloid (+/-)-alamaridine. Condensation of lithium salts of 3-cyano-4-methylpyridine and 3-cyano-4-methyl-5-vinylpyridine with a complex of 3 ,4-dihydroisoquinolines and trimethylsilyl trifluoromethanesulphonate has been studied. The amidines formed as condensation products were transformed by hydrolysis into 5,6,13,14-tetrahydro-8H-isoquino[2,1-b][2,7]-naphthyridin-8-ones, a ring system found in several alkaloids of Alangtum lamarckii. These reactions have been employed in the synthesis of the Alangium alkaloids, (±)-alangimaridine and alangimarine. The usefulness of this reaction has been further demonstrated in the synthesis of N-benzyl derivatives of 3,14-dihydronauclefine and 3,14-dihydroangustine containing 8,13,13b,14-tetrahydroindolo[2•,3•:3,4]pyrido[1,2-b][2,7]-naphthyridin- 5[7H]-one. / Thesis / Doctor of Philosophy (PhD)

Durant ce doctorat en collaboration avec Bayer CropScience, une famille de réactifs appelés Réactifs de type Fluoroalkyl Amines (ou FARs) a été étudiée (spécialement le TFEDMA) pour réaliser ’introduction de groupes fluorés émergents (EFSs). Après une activation à l’aide d’un acide de Lewis, les sels de fluoro-iminium obtenus ont été utilisés pour la difluoroacylation d’arenes et hétéroarènes riches en électrons, ou la synthèse efficace et régiosélective de pyrazoles et d’isoxazoles possédant un groupe -CHF2 à partir d’éthers vinyliques et apparentés, d’éthers d’énol silylés ou de composés CH-acides. Un nouveau FAR a été développé permettant l’introduction du groupe -CHFOCF3 sur des pyrazoles. La synthèse de nouveaux 3,5-bis(fluoroalkyl)-NH-pyrazoles a été réalisée à partir d’azines fluorées et de FARs. Une méthode régiosélective de synthèse de 3,5-bis(fluoroalkyl)-pyrazoles avec une vaste diversité structurale accessible a ensuite été développée à l’aide de cétimines fluorées, d’hydrazines et de FARs. La synthèse de bis(fluoroalkyl)pyrimidines a été développée à partir d’acétoacétates fluorés, d’amidines et de FARs. Trois produits de réarrangement de type cyclobutène hautement fonctionnalisés ont été préparés. La synthèse de pyrazoles et d’isoxazoles substitués par des groupes -CHF2 et -OCF3 a été réalisée similairement, et un exemple difficile d’acide pyrazole-3-carboxylique contenant ces deux substituants a été préparé. Le concept de FAR vinylogue a été illustré avec la préparation de l’acide 4-perfluoropropylnicotinique à partir d’iodure de perfluoropropyle. / During this 3-year PhD project in collaboration with Bayer CropScience, a family of fluorinating reagents (Fluoroalkyl Amino Reagents, FARs) was extensively studied (especially TFEDMA), and was used for various applications implying fluoro iminium salts after Lewis acid activation. The difluoroacylation of electron-rich arenes and heteroarenes was developed. The synthesis of difluoromethylated pyrazoles and isoxazoles was achieved from vinyl ethers and analogues, silyl enol ethers or CH-acidic substrates. A new FAR was developed for the facile introduction of -CHFOCF3 group. A first method was developed allowing for the first access to 3,5-bis(fluoroalkyl)-NH-pyrazoles using fluorinated azines and FARs. The regioselective synthesis of 3,5-bis(fluoroalkyl)pyrazoles with tunable regioselectivity and broad substitution scope was developed using fluorinated ketimines, hydrazines and FARs. The synthesis of bis(fluoroalkyl)pyrimidine carboxylates was successfully achieved from fluorinated acetoacetates, amidines and FARs. Three highly functionalized cyclobutene products formed by rearrangement were isolated and characterised by crystallography. The syntheses of pyrazoles and isoxazoles bearing trifluoromethoxy and difluoromethyl motifs were developed from α-trifluoromethoxy-aryl-ketones, hydrazines and FARs, and a challenging pyrazole carboxylic acid bearing both substituents was synthesized. The concept of vinylogous FAR was exemplified with the synthesis of 4-perfluoropropylnicotinic acid from perfluoropropyl iodide.

Charles University in Prague, Faculty of Science Department of Organic Chemistry Ing. Yana Chernykh Sulfur-Based Reagents for Nucleophilic and Radical Introduction of Tetrafluoroethyl and Tetrafluoroethylene Groups Ph.D. Thesis Prague 2014 ABSTRACT This project was aimed at developing new methodologies for selective introduction of tetrafluoroethyl and tetrafluoroethylene groups into organic molecules. The study was focused on reactivities of fluorinated sulfones and sulfides as tetrafluoroalkylation reagents. In the Introduction part of the thesis, main aspects of organofluorine chemistry are outlined, illustrating beneficial effects of fluorine atoms on physical, chemical and biological properties of organic compounds. General synthetic methods for the selective introduction of fluorine atoms and fluoroalkyl groups to organic molecules are described. Particular attention is given to reactivity and applications of CF2CF2-containing compounds, indicating challenges in synthetic approaches toward tetrafluoroalkylation. The Results and discussion part describes reactivities of four new fluorinated organosulfur reagents as tetrafluoroethyl and tetrafluoroethylene building blocks. The application of these reagents as various carbanionic or radical synthons proved to be effective for the incorporation of CF2CF2...