Methodenentwicklung zur Synthese und Funktionalisierung von stickstoff- und schwefelhaltigen Heterocyclen

In this dissertation, methodologies for the synthesis and functionalization of nitrogen- and sulfur-containing heterocycles applying molecular building blocks were developed. Of main interest were various sulfoximidoyl-containing heterocycles such as benzothiadiazine oxides. In the first chapter, a classical Petasis reaction of NH-free sulfoximines with glyoxylic acid and numerous boronic acids was developed, resulting in the formation of 2-sulfoximidoyl acetic acids. The synthetic application of the prepared products was validated by the synthesis of a sulfoximidoyl-containing benzodiazepine analog. Chapters two and three focused on the synthesis and application of 2-azido sulfoximines as valuable building blocks for the synthesis of diverse benzothiadiazine oxides. After the successful development of a synthetic route, their synthetic application was demonstrated in a copper-catalyzed domino reaction with iodoalkynes, combining a copper-catalyzed azide-alkyne cycloaddition and a subsequent cross-coupling, and a palladium-catalyzed domino reaction with isocyanides, combining a cross-coupling and a subsequent intramolecular cyclization. Detailed experimental studies based on the isolation of proposed key-intermediates provided insight into reaction mechanisms. In the context of the aforementioned palladium-catalyzed domino reaction with isocyanides, the analogous 2-azido sulfonamides were also investigated, which enabled the synthesis of the corresponding 2H- and 4H-benzothiadiazine dioxides. The last chapter was dedicated to new applications of sulfoximidoyl azides as building blocks for the synthesis of complex sulfonimidamides. As part of these projects, their use in the functionalization of indoles in a [2+3] cycloaddition and a carbonylative C–H amidation was successfully demonstrated.