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Metathesis in Water – A Case Study for
Supramolecular Modification of Reactivity
Miriam Sessler, Jürgen Schatz
Organic Chemistry 1, Department Chemistry and Pharmacy,
University of Erlangen, Henkestr. 42, 91054 Erlangen / Germany
Generally, metathesis reactions are carried out in organic solvents and their potential
utilization in aqueous medium is largely unexploited. The majority of methods reported
for aqueous metathesis did not use pure water as a reaction medium but only organic
solvents with some percentage of water in it. [1] However, the idea of “green chemistry”
has encouraged us to develop a simple and environmentally benign ring-closing
metathesis (RCM) protocol based exclusively on aqueous media. [2]
Here, supramolecular, water-soluble additives based on e.g. calix[n]arenes exhibit a
beneficial influence on the RCM of non-polar substrates in pure aqueous medium using
standard Grubbs-type catalyst. Additionally to (micro)solubilization of both the catalyst
and starting material by the used macrocycles, ion-pair formation of the phosphonium
ion formed in aqueous solution and the added macrocycles seem to play a crucial role in
the ring-closing reaction.
[1] S. J. Connon, M. Rivard, M. Zaja, S. Blechert, Adv. Synth. Catal. 2003, 345, 572.
[2] Th. Brendgen, T. Fahlbusch, M. Frank, D. T. Schühle, M. Seßler, J. Schatz, Adv.
Synth. Catal. 2009, 351, 303.