| In Chapter I, I give a general introduction to redox–neutral reaction cascades. In Chapter II, a Lewis acid catalyzed formation of tetrahydroquinolines via an intramolecular rodox process is described. Gadolinium triflate was proven to be a superior catalyst for this transformation. More importantly, a catalytic enantioselective intramolecular redox reaction was successfully achieved by the use of magnesium triflate in combination of a DBFox ligand. In Chapter III, a novel transformation between o-aminobenzaldehyde and secondary cyclic amines is described. This novel transformation leads to synthetically useful cyclic aminal skeletons. Two natural products, deoxyvasicinone and rutaecarpine, were synthesized directly from the oxidation of the aminal skeletons. In addition, a one-pot procedure for the synthesis of cyclic aminals promoted by Brønsted acids is also described, starting from o-aminobenzaldehydes and primary amines. In Chapter IV, non-conventional functionalizations of azomethine ylides are described. Azomethine ylides are proven to be protonated by suitable proton sources, which results in the corresponding iminium ions. Nucleophiles can attack these iminium ions, leading to synthetically useful skeletons. |
