Selective Oxidation Reactions
In many areas of synthetic organic chemistry reactions are needed, which produce in good yields stereochemical uniform compounds. In this respect many remarkable efforts have been undertaken and a variety of efficient as well as elegant stereochemical transformations using prochiral substrates are known. However, there are certain classes of compounds which cannot be efficiently used in these reactions. Only a few useful methods are known for the stereoselective functionalization of not or only weakly activated C — H bonds or C = C bonds. In our research projects we are investigating and developing stoichiometric and catalytic reactions with such compounds leading to products with new stereogenic centers.
Design and Synthesis of New Chiral Selenium Electrophiles
High stereoselectivities are obtained with very simple and easily accessible reagents. Efficient polymer-bound selenium electrophiles with all the advantages in handling and work-up have been synthesized as well.
Development of New Hypervalent Iodine Reagents
Hypervalent iodine compounds are versatile alternative reagents in reactions traditionally employing heavy metal complexes. The development of chiral reagents led to various new stereoselective reactions. Due to their high reactivity, even the functionalization of alkanes can be achieved under mild reaction conditions.
Synthesis of Natural Products
Chiral selenium reagents and hypervalent iodine compounds are being used as key reagents in the total synthesis of complex natural products with interesting biological activities.
Coordination of Chiral Ligands towards Electrophiles
We are developing a reagent -controlled stereoselective iodolactonization reaction applying a new method by using a combination of ICl and a chiral primary amine as chiral ligand to the I+ cation.
The selective functionalization of alkenes by combining electrochemical methods with electrophilic reagents leads to promising catalytic reactions. The direct electron transfer at electrode surfaces is frequently referred to as one of the prototypical green technologies of the future.
The evaluation of reaction pathways, transition states, intermediates and mechanisms by close interaction of therory and experiment on various levels is supporting many of the research areas mentioned above.
Microreactors in Chemistry
Modern organic synthesis is undergoing a period of rapid change due to the many demands challenging it today. The introduction of more general platforms to perform reactions under continuous flow rather than in batch mode has led to improvements regarding safety and sustainability. Many reactions can benefit from the physical proper¬ties of microreactors, such as enhanced mass- and heat transfer due to a very large surface to volume ratio as well as regular flow profiles leading to improved yields with increased selectivities. Strict controls over thermal or concentration gradients within the microreactor allow new methods for efficient chemical transformations with high space-time yields.