Library of Dynamic Covalent linkers

The ideal template for the selection of the best catalyst is the transition state, which is by definition unstable and therefore not useful. Therefore, a TSA should be designed that, on the one hand, is sufficiently precise to mimic the transition state but, on the other hand, is sufficiently stable to be used for the selection procedure. Recent progress in molecular modehng and the ever-increasing computer power facilitates the identification of the transition state and for the design of analogs thereof. 

No successful example has been reported so far using a TSA in a dynamic combinatorial approach to transition metal catalyst selection. However, inspired by enzymes and molecular cages, molecularly imprinted polymers were successfully developed by WuUF et al. and in a small number of cases directed towards transition metal catalysis [22]. Cavities as biomimetic catalysts are created by generation of polymeric materials in the presence of a TSA as a template, which is removed after polymerization. In the presence of the substrate, the incorporation of the catalyst precursor leads to high activities, the transition state being stabilized by the polymeric cavities. 

Metal center , bond involved in the dynamic exchange Q, coordination site (P, N, 0, S, 

The field of dynamic combinatorial catalysis is virtually open. The first few examples, however, provided first proof-of-principle that also in this area DCC has added value. For both cage-type catalysts as well as transition metal complexes the DCC approach could have significant advantages over rational design or traditional combinatorial strategies, but at this stage it is far too early to compare these approaches. In this chapter, we mainly focus on the principles, supported by some initial results, in the hope that we will stimulate scientists to continue research in this exciting new area. 

Crabtree, R.H. (2005) The OrganometalUc Chemistry of the Transition Metals, Wiley-VCH Verlag GmbH, Weinheim. 

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