Timothy Noel

Visible-light photoredox catalysis in flow – Towards a sustainable production of pharmaceuticals

Visible light photoredox catalysis has received much attention in recent years as a mild and sustainable activation mode for organic molecules.[1] In particular, when coupled with microreactor technology, an efficient irradiation of the reaction medium is achieved.[2] Yet, the use of solar energy to promote visible light mediated reactions is not widespread and adopts energy-inefficient systems like the “flask in the sun”. The efficient use of solar light as perennial energy source in the fine chemical production industry can reduce the dependence on fossil fuels and enable the transition toward a world driven by clean energy.

In this lecture, we will discuss on our work concerning the development of novel synthetic methods using photoredox catalysis and how these methods can benefit from continuous-flow processing.[3] Furthermore, we will discuss a novel device integrating the luminescent solar concentrator (LSC) concept with photomicroreactors (LSC-PM), allowing the direct use of solar light in photochemistry without the need for any intermediate energy conversion.[4] This device is capable of capturing direct and diffuse sunlight, converting it into a narrow wavelength and delivering it to the embedded microchannels. Finally, automation strategies will be detailed upon, including an automated approach to facilitate Stern-Volmer and other luminescence quenching studies[5] and a real-time reaction control unit to cope with variable weather conditions.[6]

REFERENCES

[1] C. K. Prier, D. A. Rankic and D. W. C. MacMillan, Chem. Rev., 2013, 113, 5322-5363.

[2] D. Cambié, C. Bottecchia, N. J. W. Straathof, V. Hessel, T. Noel, Chem. Rev. 2016, 116, 10276-10341.

[3] For some of our most recent work: [a] G. Laudadio, S. Govaerts, Y. Wang, D. Ravelli, H. Koolman, M. Fagnoni, S. Djuric, T. Noel, Angew. Chem. Int. Ed. 2018, 57, 4078-4082. [b] X.-J. Wei, W. Boon, V. Hessel, T. Noel, ACS Catal. 2017, 7, 7136-7140. [c] C. Bottecchia, M. Rubens, S. Gunnoo, V. Hessel, A. Madder, T. Noel, Angew. Chem. Int. Ed. 2017, 56, 12701-12707. [d] N. J. W. Straathof, S. E. Cramer, V. Hessel, T. Noel, Angew. Chem. Int. Ed. 2016, 55, 15549-15553.

[4] [a] D. Cambié, F. Zhao, V. Hessel, M. G. Debije, T. Noel, Angew. Chem. Int. Ed. 2017, 56, 1050-1054. [b] D. Cambié, F. Zhao, V. Hessel, M. G. Debije, T. Noel, React. Chem. Eng. 2017, 2, 561-566. [c] F. Zhao, D. Cambié, J. Janse, E. Wieland, K. P. L. Kuijpers, V. Hessel, M. G. Debije, T. Noel, ACS Sustain. Chem. Eng. 2018, 6, 422-429.

[5] K. P. L. Kuijpers, C. Bottecchia, D. Cambie, K. Drummen, N. Koenig, T. Noel, Angew. Chem. Int. Ed. 2018, 57, 11278-11282.

[6] F. Zhao, D. Cambié, V. Hessel, M. G. Debije, T. Noel, Green. Chem. 2018, 20, 2459-2464.