Organic chemistry poster symposium

Non-mechanically interlocked processive catalysis using directionally sequential C–H functionalisation

E.L. Hollis 1 , M. Chronias 1 , P. Gobbo 2 , B.S.L. Collins 1 1 University of Bristol, UK, 2 University of Trieste, Italy

Autonomous chemically-fuelled directional motion underpins the function of many of nature’s biological motor proteins such as DNA polymerase, which acts upon a strand of DNA to replicate its sequence. 1 Many of these enzymes exhibit processivity, where the enzyme remains associated with the biopolymeric thread through multiple rounds of catalysis. Synthetic efforts have been undertaken to mimic these enzymes whereby a macrocyclic catalyst acts to modify sites along a molecular thread. 2,3 The aim of this project is to develop a non-macrocyclic processive catalyst which is chemically (covalently) bonded to the polyaromatic thread on which it performs work. Towards this goal, we have successfully realised the rhodium-catalysed processive alkylation of a small biaryl thread (Scheme 1C). Drawing on the rhodium-catalysed iterative insertion of norbornene reported by Miura and co-workers (Scheme 1A), 4 this methodology combines iterative C–H functionalisation with [1,4]-metal migration (Scheme 1B) to directionally functionalise along a polyaromatic thread.

We have demonstrated that this methodology is compatible with [1,5]-metal migration and can be applied to longer polyaryl threads. Mechanistic studies support our hypothesis that the catalysis proceeds in both a processive and directionally sequential manner. Extension of this methodology may have applications in information storage, molecular devices, and artificial active transport of a rhodium catalyst. References

1. Breyer, W.A. and Matthews, B.W. Sci . 2001 , 10, 1699. 2. Rowan, A.E. and Nolte, R.J. et al. Nature . 2003 , 424, 915. 3. Takata, T. et al. Com . 2010, 46 , 1920. 4. Miura, M. et al. Am. Chem. Soc. 2000 , 122 , 10464.

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© The Author(s), 2023

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