Page
%P
-
Article
Intramolecularly Friedel-Crafts Acylated Emodin Derivatives. An Access to the Cores of Angucyclinones, Anthracyclinones, and to Hypericin Analogues
Intramolecularly emodin based Friedel-Crafts acylation provided a new route for the synthesis of the angucyclinone and anthracyclinone core as well as access to a new class of cyclopentanone condensed anthraquino...
-
Article
Syntheses, Photochemical Properties, and Tautomerism of Intramolecularly Friedel-Crafts Acylated Hypericin Derivatives
Intramolecularly Friedel-Crafts acylation carried out on the hypericin moiety provided a new class of 9,12-dicarbonyl substituted hypericin derivatives as potential candidates for photodynamic therapy (PDT). Focu...
-
Article
9,12-Dibenzothiazolylhypericin and 10,11-Dibenzothiazolyl-10,11-didemethylhypericin: Photochemical Properties of Hypericin Derivatives Depending on the Substitution Site
Investigating the properties of similar but regioselectively differently substituted hypericin derivatives, 9,12-dibenzothiazolylhypericin was synthesized and compared with the recently prepared 10,11-analogue...
-
Article
In vitro study of the photocytotoxicity of bathochromically-shifted hypericin derivatives
Hypericin has excellent photosensitizing properties and displays favorable tumouritropic characteristics, but at the same time exhibits minimal dark toxicity. As such, the compound is a promising photosensitiz...
-
Article
Open AccessA remarkable cyclization of TADDOL-bisthioacetate under oxidative conditions
Attempted oxidation of a TADDOL-derived bisthioacetate resulted in a rather unexpected and remarkable cyclization and deprotection reaction, giving a thiolane-1,1-dioxide as the main product. Systematic in sit...
-
Book
-
Chapter
Conclusions
The field of natural product syntheses has been dominated by (transition-) metal catalyzed asymmetric reactions for decades. However, besides the very broad range of different transformations that can be achie...
-
Chapter
Introduction
The field of natural product syntheses has been dominated by (transition-) metal catalyzed asymmetric reactions for decades. However, besides the very broad range of different transformations that can be achie...
-
Chapter
Singly Occupied Molecular Orbital (SOMO) Catalysis
The field of natural product syntheses has been dominated by (transition-) metal catalyzed asymmetric reactions for decades. However, besides the very broad range of different transformations that can be achie...
-
Chapter
Asymmetric Oxidations and Reductions
The field of natural product syntheses has been dominated by (transition-) metal catalyzed asymmetric reactions for decades. However, besides the very broad range of different transformations that can be achie...
-
Chapter
Combined Iminium-Enamine Catalyzed Approaches
The field of natural product syntheses has been dominated by (transition-) metal catalyzed asymmetric reactions for decades. However, besides the very broad range of different transformations that can be achie...
-
Chapter
Asymmetric Phase-Transfer Catalysis
The field of natural product syntheses has been dominated by (transition-) metal catalyzed asymmetric reactions for decades. However, besides the very broad range of different transformations that can be achie...
-
Chapter
Iminium Catalysis
The field of natural product syntheses has been dominated by (transition-) metal catalyzed asymmetric reactions for decades. However, besides the very broad range of different transformations that can be achie...
-
Chapter
Chiral Brønsted Acids and Hydrogen Bonding Donors
The field of natural product syntheses has been dominated by (transition-) metal catalyzed asymmetric reactions for decades. However, besides the very broad range of different transformations that can be achie...
-
Chapter
Enamine Catalysis
The field of natural product syntheses has been dominated by (transition-) metal catalyzed asymmetric reactions for decades. However, besides the very broad range of different transformations that can be achie...
-
Chapter
Chiral Brønsted and Lewis Bases
The field of natural product syntheses has been dominated by (transition-) metal catalyzed asymmetric reactions for decades. However, besides the very broad range of different transformations that can be achie...
-
Article
Photoreactive, water-soluble conjugates of hypericin with polyphosphazenes
The naturally occurring drug hypericin has invoked much interest in a wide variety of biomedical applications as an antiviral, antibacterial, or antitumor agent, as well as its use as a photosensitizer for pho...
-
Article
Thin layer chromatography–spray mass spectrometry: a method for easy identification of synthesis products and UV filters from TLC aluminum foils
A straightforward procedure for direct mass spectrometric (MS) analysis of spots from thin layer chromatography (TLC) plates, without the need of an external ion source, was developed using the aluminum plate ...
-
Article
Asymmetric α-chlorination of β-ketoesters using bifunctional ammonium salt catalysis
Chiral urea-quaternary ammonium salt hybrid organocatalysts were tested for their capability to control asymmetric α-chlorination reactions of β-ketoesters. After a careful screening we identified a structural...
-
Article
Open AccessOn the origin of the stereoselectivity in chiral amide-based ammonium ylide-mediated epoxidations
Detailed DFT studies provide an in-depth mechanistic understanding for the use of chiral amide-based ammonium ylides in epoxidation reactions. It is shown that the used chiral auxiliary efficiently shields one...
