Semiconductor Catalyzed Addition Reactions Driven by Visible Light

• Applicant: Professor Dr. Horst Kisch
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2000 to 2004
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5247606

Aim of this project is to develop solar syntheses of fine chemicals having potential biological activity. This shall be accomplished through visible light-driven addition reactions between unsaturated substrates catalyzed by semiconductor powders. Addition reactions in generally are environmental friendly processes since they do not produce useless by-products. As recently discovered in the laboratory of the german group, cadmium sulfide powders photocatalyze the addition of olefins to imines affording hitherto unknown homoallyl amines. In the case of an imino ester the product is an unsaturated a-amino acid ester, which can be easily converted into the corresponding a-imino acid. According to the first mechanistic investigations the semiconductor photocatalyzes a proton-coupled double electron transfer between donor and acceptor substrates. This unconventional heterogeneous photosensitization mechanism opens a wide field in solar syntheses of fine chemicals. Before this can be successfully explored, some basic mechanistic knowledge has to be gained. This work shall be performed in Erlangen due to the experience of this group in semiconductor photocatalysis. Since the Izmir group has already conducted solar chemical reactions, the solar synthesis of the amino acid esters will be executed there.

• DFG Programme: Research Grants
• International Connection: Turkey
• Participating Person: Professor Dr. Siddik Icli