Organocatalysis - Application in Total Synthesis

• Applicant: Dr. Nicole Holub
• Subject Area: Organic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2008 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 71084015

Chiral carbonyl compounds containing alkenes and alkynes play a very important role in chemistry. However, the asymmetric catalytic conjugate alkenylation or alkynylation was up to now limited to metal-based reactions, and in addition, different conditions were required to achieve either the alkenylic or alkynylic product. -Keto heterocyclic sulfones have been developed as new nucleophilic reaction partners, which after an organocatalyzed conjugate enantioselective addition, furnish a highly potential class of substances. Depending on the applied conditions, these structures can be transformed either into the corresponding alkenylic or alkynylic compound. The conjugate addition to,-unsaturated aldehydes and ketones has been already established during the last months and two manuscripts are in the process being written at the moment. The aim of the following proposal, and therefore, for the extension of the postdoctoral stay, is to apply this new methodology to other reactions. The first part is closely related to the examination of these nucleophiles in different 1,4- and 1,2-additions, while the main part deals with the extension of this compound class to electrophilic structures and their utilization in domino reactions. Furthermore, the efficiency of all concepts will be proved in the synthesis of natural products. Despite the synthesis of -mino acids like -DOPA or ADDA, investigations directed towards the synthesis of plakorine A, a 2-alkylidene substituted pyrrolidine, will be carried out.

• DFG Programme: Research Fellowships
• International Connection: Denmark
• Host: Professor Dr. Karl Anker Jørgensen