TiO2 in Organic Photosynthesis: Sunlight Induced Functionalization of Heterocyclic Bases

In the last decades photocatalyzed organic processes have attracted the great interest, due to their low environmental impact. Various oxidation and reduction processes of organic substrates have been developed as alternative routes to the "classical" synthesis of more complex molecules. In this attempt TiO2 is actually largely studied and employed, especially as catalyst in the organic pollutants photodegradation to products with less environmental impact. From the synthetic point of view, the attention has been focused particularly on the TiO2-mediated synthesis of alcohols, carbonyl- and carboxylic-derivatives. Recently our group has developed new TiO2-photocatalyzed synthetic protocols for the functionalization of N-heteroaromatic bases as an alternative to the "classic" well known redox metal-catalyzed methods. These substrates are suitable for the nucleophilic free-radical addition and the photocatalytic activity of microcrystalline TiO2 has shown a key role in the success of our protocol.