Hyderabad scientist develops greener experiment



HYDERABAD: This year the Nobel Prize in chemistry was awarded to Barry Sharpless, Morten Meldal, and Carolyn Bertozzi for their work in click chemistry and biorthogonal chemistry. Though click chemistry, which has simplified the life of chemists, is indeed revolutionary, it is said to be unhealthy in terms of the environment. A leading researcher in chemistry from the city has gone a step further, making the click chemistry healthier and green.
Prof DB Ramachary of the School of Chemistry, University of Hyderabad has developed a similar one-click reaction, which is greener, healthier and environment-friendly. The one-click or one-pot experiment has simplified the life of chemists by building molecules simply at a snap.
This means the regular trend of making molecules with difficult steps in a chemical laboratory is now simplified, wherein two molecules are bound together like a self-sealing cover or the two ends of the seat belt unified to give a tight joint. It also helps in easy finding of drugs for various diseases. The one-click model of Prof Ramachary is considered advanced and more simple.
According to Prof Ramachary, the story of one-click experiment began in the early 2000s when Sharpless and Meldal working independently, discovered a new reaction using terminal alkynes and various azides for the synthesis of certain chemicals called 1,4-disubstituted 1,2,3-triazoles that have numerous applications in all fields of science. It also helps in making synthetic molecules that impart a broad spectrum of biological properties like anticancer, antiproliferative, inhibitory, antiviral, antibacterial, antifungal, antiallergic, and antioxidant properties. This reaction was named click reaction by Sharpless.
Though this process is highly innovative and widely applicable, it does have a few drawbacks, said Prof Ramachary adding that it works only for terminal alkynes and not for internal alkynes. And alkynes are not easy to synthesize. Hence they are very costly.
To address these problems, Prof Ramachary discovered another method to synthesize 1,2,3-triazoles. Though there are many scientists, who came up with different ideas using metal catalysts like rhodium, ruthenium, silver, etc, none of them proved to show efficient selectivity than the initial copper-catalysed reaction.
But it was Prof Ramachary and his group, who made this entire process greener by developing a novel metal-free click reaction by using highly stable, cheap and readily available starting materials like alpha methylene carbonyl compounds and aryl or alkyl azides in the presence of amino acids as catalysts.