The synthesis of N-substituted ferrocenes and CH activation towards the synthesis of Organosilanols
In the present thesis, a Ru-catalyzed diastereoselective ortho-silylation of ferrocenyl oxazolines was achieved in poor to good yields and moderate to high diastereomeric ratios. To the best of our knowledge, this is the first catalytic and diastereoselective C–H activation on ferrocenes. After screening many other directing groups, only ferrocenyl ethanol and pyrazoles furnished the desired ortho-silylated product. The synthesis of planar-chiral ferrocene-based organosilanols was also described. High enantioselectivities and yields of up to 91 and 87%, respectively, have been achieved in collaboration with Frank Schmidt using both zinc and boron-based aryl sources. Although silanols gave lower yields and enantiomeric excesses compared to carbinol analog, to the best of our knowledge this is the first application of chiral organosilanols in asymmetric catalysis. In the last part of the thesis, a simple and efficient method for the preparation of various N-substituted ferrocene by Ullmann type coupling reaction mediated by copper(I) iodide was presented. Attractive features of this protocol are the direct synthesis of such valuable compounds by C–N bond formation and the use of simple and cheap reagents (metal salt and base).
info:eu-repo/classification/ddc/540, Chemie, Asymmetrische Synthese, Ferrocen, Aktivierung, Katalysator, Chirale Verbindungen, Asymmetric Synthesis, Ferrocene, C-H Activation, Chiral Catalyst
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