Currently, many of the important chemicals found in medicine and agriculture are manufactured using long-known techniques that rely on the use of expensive, toxic metals, and the use of thermal energy in the form of heat. A key aim for chemists is to both expand the toolbox of chemistry to enable the synthesis of new chemicals, and to improve the efficiency and sustainability of manufacturing. In very recent times, the use of visible light as a source of energy to drive chemical reactions has become a topic of great interest, since both new reactions can be developed and without the requirement for excessive heating. Visible light is a far more sustainable source of energy compared to heat.
In this regard, the aim of the project was to investigate the use of visible light for the discovery of new chemical reactions. Specifically, the aim was to use isothiourea catalysts (organocatalysts), which are cheap, non-toxic, and easily made, and combine their use with photochemical activation, to synthesize molecules which may be of biological importance.
This was realized by combining isothiourea catalysts with photoredox catalysis, which has enabled the construction of complex chiral molecules from readily available and cheap starting materials. New isothiourea catalysts were developed and used in this technology alongside organic, metal-free photoredox catalysts, which constitutes a sustainable method which has been shown to be useful for making biologically relevant molecules.
New ways to make biologically active chemicals are sought-after in both academic and industrial settings. This is due to the potential advantages of newly discovered methods that may include reduced cost, toxicity, environmental impact, safety risks and operational difficulties. From an industrial point of view, the project has led to the development of a sustainable method for the production of chiral chemical products that may be of interest to the pharmaceutical and agrochemical industries. Therefore, the project has the potential to impact society beneficially by improving the manufacture of chemicals.
The overall objectives for the project were to establish a platform for the use of visible light as an energy source in isothiourea-catalysed chemical reactions.
