ausblenden:
Schlagwörter:
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Zusammenfassung:
This doctoral work describes the preparation of carboxylic acid derivatives from unsaturated hydrocarbons via the synthesis of a versatile acid chloride intermediate, a new strategy to access aryl iodides and the oxidation of alkanes to diols.
In the first part, a shuttle catalysis approach enables a CO- and HCl-free transfer process between an inexpensive reagent, butyryl chloride, and a wide range of unsaturated substrates to access valuable acid chlorides. This elusive Pd-catalyzed transformation,
virtually unknown using traditional approaches such as the Reppe-type carbonylation, provides a general entry into the laboratory-scale preparation of a plethora of CO-containing
products through the in situ derivatization of the reactive acid chloride intermediate (Scheme 0.1.).
In the second part, aroyl chlorides were efficiently converted to aryl iodides through decarbonylative iodination (Scheme 0.2.). Its key feature is the use of a Pd0 precursor in
combination with the bidentate phosphine ligand Xantphos. An unprecedented sequence of subsequent reversible oxidative addition of acid chloride at Pd0, decarbonylation, halide
exchange and reductive elimination at PdII was added to the portfolio of Pd-catalyzed reactions. This concept certainly opens a new route toward the one-pot conversion of aroyl
chlorides to form C–X bonds.
In the third and last part of this thesis, the selective oxidation of unactivated alkanes to
vicinal diols is described. With cyclohexane as substrate, the transformation enables the selective formation of trans-1,2-cyclohexanediol in very good yields (Scheme 0.3.). Its key
feature is the use of a Brønsted acid, HBF4, in combination with trifluoroperacetic acid as oxidant. This strategy also bears the potential to transform alcohols to vicinal diols, a
significant advantage that could be exploited in synthetic chemistry.
