Organocatalysis ­- A Greener Molecule

Francis Hemsworth outlines and argues for the use of Organocatalysis as a more sustainable cataylist.

A whopping 90% of all commercially ­produced chemical reactions use a catalyst.

Unsurprisingly, this amounts to an enormous ~$34 billion valued catalytic market. With a projection of the market continuing to grow at an estimated 4.5% year on year until 2027, it cannot be disputed, then, that there is a great demand for research in this area.

As such, recent studies have made scientific media coverage ­just last week (at the time of writing) when the Nobel Prizes were distributed, the wonderful field of organocatalysis was awarded its first prize. The work, carried out by Ben List and David MacMillan, focused on organocatalysis a brand new, more sustainable type of catalysis which uses small organic molecules, such as proline or phenylalanine (both amino acids), to speed up reactions, as opposed to expensive metal catalysts or more toxic molecules.

The problem with the current catalytic market is that whilst the function of catalysts themselves is to reduce waste, the catalyst being used is either non­sustainable or highly toxic to the environment. Many of the non­sustainable metals are expensive, with platinum being a prime example. Furthermore, some are highly toxic to the environment ­ like sulfuric acid, or worse, hydrofluoric acid. This is precisely where organocatalysts come in to fix the job!

Given that the majority of organocatalysts are amino acids, these solve the above problem as well as two other major problems. The first problem it potentially corrects is the one concerning sustainability. Amino acids are naturally found in the body and hence can be sourced from a variety of organisms ­ nuts, beans, plants, or meats. Since the demand of soybeans, for example, is going through the roof due to its versatility as a meat substitute, it’s no stretch to think that the supply of certain organocatalysts could easily be thrown into the mix, granting ample supply.

The second widespread problem for catalysts is simply finding which one fits a specific reaction. The helpful facet of amino acids is that there happens to be only 20, saving chemists a generous amount of time by only needing to test a few out for each and every reaction.

The last problem ­although not so much a problem as an advantage ­ is that whilst there are only a limited number of non­organocatalysts in the periodic table, maybe only 30, amino acids have long been known to form more complicated proteins which mount easily into the hundreds of thousands. Some of these simpler proteins may hence have business in becoming effective organocatalysts.

These benefits seem to make organocatalysts not only the future of sustainable catalysts but the future of catalysts in general. Additionally, it is worth concluding that organocatalysis has at best maybe a decade’s worth of true research, and with its best years to come, it’s my hope that it will be able to create a greener molecule.

From SATNAV Issue 23, pages 7-8.