Thiruvananthapuram: When the Danish carpenter Ole Kirk Christiansen started selling LEGO wooden toys, little did he know that it would become one of the most powerful brands in the world.
Imagine his surprise if he learned that Lego toys were going to inspire Ei-ichi Negishi, a Japanese scientist, to make a Nobel-prize winning invention.
The chemist retold the story at Mascot Hotel while delivering his lecture on Transition Metal Catalysis for a Sustainable and Prosperous World
In the 1960s, when he was a second-year student at the University of Pennsylvania struggling to learn English, Lego was fast gaining popularity.
“It had invaded America. In a Lego game, you need two pieces. One with a hole, one with a stick. That’s all you need. That gives you a generality. You just keep snapping the two pieces, and all of a sudden you get a house, or an aeroplane or a luxury car. I thought organic synthesis should be done that way. Out came cross-coupling,” he says.
Cross-coupling, he went on to explain, has an electrophile, and an electron-rich, nucleophile–two pieces which could be snapped together.
However what was critically missing at that time was a metal catalyst, which would speed up the process, he said. He would later discover that palladium would serve as an ideal metal catalyst for cross-coupling.The process is known as Negishi coupling.
He referred to the steps in the synthesis of various organic molecules as ‘LEGO Game Routes’, during his presentation. He could confirm using NMR spectroscopy that the number of steps involved was far less, as compared to methods used by his contemporaries.
The research establishing the efficacy of Negishi coupling spanned a quarter of a century, he said. Scientists have been using the coupling to synthesise new molecules. Negishi, towards the end of his lecture, said, “We have conquered the last bastion in organic synthesis.”
