Transition Metal Catalyzed Transformations for Synthesis of Complex Organic Molecules
| Autor: | Kawade Rahul Kisan, 羅湖 |
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| Rok vydání: | 2015 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 103 This dissertation describes development of new synthetic organic transformations by using gold or copper metal salts. The use of these metals enables mild, selective and efficient oxidative transformations of readily available substrates to wide range of synthetically useful nitrogen, oxygen and sulfur containing complex organic molecules. For better understanding the thesis is divided into four chapters. The first chapter deals with the Gold-catalyzed oxidative cyclization of 4-allenyl-1-ynes with 8-methylquinoline oxide. The catalytic reaction produces diverse products bearing N and O heterocycles depending on the allenyl substituents. This reaction comprises initial formation of α-oxo gold carbenes that are attacked by allene to form allyl cation intermediates which either undergoes elimination or nucleophilic addition to afford diverse cyclic products. The results obtained here manifested that the intermediate α-oxo-gold carbenes has carbocation character. The second chapter deals with the Cu-catalyzed aerobic oxidative Mannich reactions with a skeletal rearrangement of N-hydroxyl propargylamines. These aerobic oxidations of readily available 3-N-hydroxyaminopro-1-ynes with water, alcohols, or thiols afford diverse 3-substituted 3-amino-2-en-1-ones. We developed cascade or sequential reactions of allylic alcohols, alkynols, and allenols, to involve a Claisen rearrangement or gold catalyzed cyclizations, providing new products with molecular complexity. The third chapter describes the Cu-catalyzed oxidative Povarov reactions between N,N-dialkylanilines and saturated oxa- or thiacycles with tert-butyl hydroperoxide (TBHP) to form tetrahydroisoquinoline derivatives. The use of cheap alkane based substances as four- and two-atom building units is of mechanistic and practical interest, this work also represents the first achievement of catalytic [4+2]-cycloaddition using neither [4p]- nor [2p]-motifs initially. The fourth chapter presents gold-catalyzed syntheses of 2,3-disubstituted indole derivatives from N-hydroxyanilines and allenes; with benzaldehyde as an additive to generate nitrones in situ. This synthetic method is compatible with reasonable range of allenes and N-hydroxyanilines, thus further highlighting its synthetic utility. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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