What are Catalysts?

Many of the chemical reactions occur naturally by just introducing the various chemicals together and voila. For others, there are catalysts. Catalysts enable the chemical reaction to speed up or reach the right temperature or pressure needed to start the reaction. They are not consumed directly in the reaction and remain unchanged after the reaction.

Catalysts can be broadly categorised into 4 major types:

Homogeneous Catalysts, where both the reactants participating in the reaction and the catalyst, are both present in the same phase.

Heterogeneous Catalysts, where the reactants participating in the reaction and the catalyst, are in different phases.

Heterogeneous Homogeneous Catalysts, where the homogeneous catalyst is grafted onto the solid supports to prepare their heterogeneous analogues.

Biocatalysts, where naturally occurring proteins and nucleic acids are used to carry out the chemical reaction.

Organic Synthesis is the process of a series of chemical reactions that are designed to form organic compounds. Organic molecules are often more complex than inorganic compounds and organic synthesis forms the basis of replication of molecules of living nature. This process is hence used widely to prepare compounds for critical industrial, commercial and medical use.

What are the New-Age Catalysts that can be used for Organic synthesis?

Metal catalysts like Palladium, Platinum and Iridium are commonly used for organic synthesis, especially in the pharmaceutical space. While these are normally removed from the chemical process after the synthesis, their toxicity remains a point of concern, and there is a risk of traces remaining in the compound.

Here are some new-age catalysts and strategies that can prove promising in organic synthesis:

Iron Catalysts: Iron is a lesser evil in terms of toxicity and is abundantly available. They also do not require special storage conditions and can prove to be economically viable.

Organocatalysts: Non-metals like carbon, nitrogen and hydrogen along with minor amounts of other elements. It solves the problem of residual traces of the catalyst.

Metal-Organic Frameworks: Metal-Organic Frameworks, also called MOFs, with their high degree of tunability and stability are one of the solutions as new-age catalysts. Controlled insertion of defects are used to alter the properties of MOFs in a planned manner.

Dual Catalysis: Dual catalysis can be an effective solution for complex organo-synthesis. These methods can use a combination of metal catalysts, organocatalysts, photocatalysts, and biocatalysts. It can prove a solution for challenging transformations, control the stereoselectivity of asymmetric reactions and catalyse the stereo-divergent synthesis of molecules with one or multiple stereocenters.

Enzyme Metal Hybrid Catalysts: Enzyme-metal hybrid catalysts (EMHCs) combine the merits of both enzyme and metal catalysts with high selectivity, efficiency, and broad-substrate spectrum and can prove to be ideal catalysts for organic synthesis.

Conclusion

There is conclusive evidence that usage of new-age catalysts can prove to be effective in organic synthesis, and decrease the risk of toxicity in pharmaceutical processes. There is more research and adaptability required to make these processes widely used on a large scale in industrial and pharmaceutical processes.