Substituted hetera[n]helicenes and the applications in enantioselective synthesis

Promovendus/a: Mathias Daniels

Promotor(en): Prof. dr. Wim Dehaen

Chiral catalysts have become very important for chemical research and industry. One of the main disadvantages is the complexity and cost for synthesis and purification. In most cases there is no perfect selectivity and only a moderate stability. Moreover the regeneration of catalyst is almost impossible. The stability of helicenes is excellent as they are robust polyaromatic systems that can be modified after synthesis to obtain a catalyst with optimal properties. Helicenes are resistant to high temperatures, strong acids and bases and oxidizing or reducing agents thatare often used in chemical reactions. The helicenes can be immobilized on a solid phase to make regeneration easy. For the moment there is no known method to obtain enantiomerically pure helicenes in substantial amounts. One of the goals in this project is to develop an efficient methodfor the synthesis of new benzo fused hetera[5]helicenes with substituents to prevent racemisation. We also plan to use this method for the synthesis of helicenes with substituents that can be used for organocatalysis. The synthesis of homochiral helicenes directly from a non-chiral precursor through catalysis with readily available chiral additives in an oxidative cyclisation reaction will be developed in our group. The obtained compounds will be tested for their properties as catalyst for enantioselective reactions.