By Joshua Britton (Supervisor – Colin Raston)
Flow chemistry is a thriving area in the chemical sciences due to the ability to synthesise large volumes of complex organic molecules in a short time whilst utalising green chemistry parameters. Flow chemistry is essentially tailoring organic reactivity to occur within channels, tubes or in the case of current work, thin films. The Vortex Fluidic Device (VFD) is a thin film microfluidic processing platform that allows synthetic strategies to be incorporated into thin films in a continuous flow manner. The VFD consists of a commercially available NMR tube that is spun at high rotational speeds. The fluid inside the tube forms a dynamic thin film where by all molecules are treated equally and are subjected to physical properties such as micromixing, increased shear stress rates and novel fluid dynamical responses such a Faradaic fluidic flow. My work is focused on harnessing the aforementioned physical properties in synthetic modifications to allow greener, novel methodology to emerge in flow chemistry.
With traditional flow systems now making high molecular mass, complex natural products, the aim of current work is an understanding of the VFD, and how to control the numerous control parameters. My work has elucidated the control parameters of the device, and a large element of control has now been gained. It is now possible to optimise an organic reaction through following a simple set of rules and optimisations. Such reactions occur in a continuous flow system, operating at room temperature, with improved green chemistry metrics whilst maintaining excellent to quantitative yields. Organic modifications that have been achieved/ currently studying thus far are;
- Nucleophilic substitution/ addition/elimination
- Catalyst free sp2 modifications
- Intramolecular cyclisations
- Rapid amide bond formation
- Imine and α-phosphonate synthesis
- Natural products found within fertilisers and agrochemicals via [2+3] cycloaddition.
With such methodology impacting contemporary synthesis, we applied such methodology to biodiesel generation and transformation. We were able to make high purity biodiesel using a novel sets of parameters that allows not only room temperature transformations using significantly less starting material, but also a huge reduction in time, cost and the targeting of new, problematic feedstocks.
[1] J. Britton, S. B. Dalziel and C. L. Raston, RSC Adv., 2014, DOI: 10.1039/C4RA11777H
[2] J. Britton and C. L. Raston, RSC Adv., 2014, 4, 49850-49854
[3] J. Britton and J Camp, Catalysis Application, Chemistry Today, 30, 2012
[4] J. Britton and C. L. Raston, RSC Adv., 2014, Accepted.