Hetero-Sequenced Cage Compounds as Bio-Inspired Molecular Flasks

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The efficient catalysis of chemical reactions is of substantial importance to modern society. For the development of new catalysts, The efficient catalysis of chemical reactions is of substantial importance to modern society. For the development of new catalysts, chemists are often inspired by nature.Natures catalysts are enzymes. Those can catalyze chemical reactions with great precision and efficiency. The reactions take at active sites place, which are in protected unsymmetrical pockets located. While the precise structure of most reactive sites is known, their exact way of how they operate is often not sufficiently understood.In this project the unsymmetrical pockets and active sites of enzymes will be through the use of synthetic compounds mimicked. Those mimics will be through the synthesis of new cage compounds obtained. The here synthesized cage compounds will offer unsymmetrical cavities that are similar to the unsymmetrical pockets of enzymes. Reactive sites that can catalyze chemical reactions will be in those synthetic cavities located. The cavities will be through the application of new synthetic concepts obtained. Through the use of these new synthetic and unsymmetrical cage compounds, it is aimed to mimic enzymes with an unprecedented precision. To mimic enzymes follows here two objectives.The first is the development of new catalysts, which should be able to choose their reaction partner based on their size. The selection occurs through the cage compound. This offers pores of a defined size, preventing undesired reaction partner to reach the cage interior where the active center is located. This concept of size-selective catalysis should be applied to the oxidation of organic compounds. Catalysts that are based on iron, manganese and copper will be used for the oxidation reactions. Size-selective catalysis can be of potential interest for the synthesis of pharmaceuticals or fine chemicals. In addition, it is important for the conversion of crude oil or biomass.The second goal is to obtain a better understanding on how active sites of important enzymes operate. To achieve this, models of these sites will be in the cage compounds reassembled. The cages will protect the sites and allow an easier investigation of those. Two very important motifs will be in particular studied. The first is an iron-complex, which is in enzymes that can catalyze many important oxidation reactions (among others the synthesis of penicillin). The second is the so-called iron-molybdenum-cofactor, which can transform nitrogen into ammonia. Ammonia is for the production of food of very high importance. Knowledge gained during this project may lead to the development of more efficient catalysts for ammonia synthesis.