Chemists have discovered that a cheap, safe to use and common in nature potassium compound can be used as a catalyst in the production of important chemicals for the pharmaceutical, agricultural and medical imaging industries, instead of expensive and rare metals.
[Translation by Dr. Moshe Nachmani]
Chemists have discovered that a cheap, safe to use and common in nature potassium compound can be used as a catalyst in the production of important chemicals for the pharmaceutical, agricultural and medical imaging industries, instead of expensive and rare metals.
A team of chemists from the California Institute of Technology (Caltech) has discovered a method to create a group of sulfur-based organic chemicals without relying on rare and expensive metal catalysts. Instead of these catalysts, their innovative method utilizes a cheap and common chemical that is used chemically in every laboratory around the world - potassium tert-butoxide (Wikipedia) - as the catalyst, in order to assist in the production of a variety of products, from new drugs to advanced materials. The researchers discovered to their astonishment that the catalyst is much more effective than all the most advanced precious metal conjugates in their field that are used as catalysts for particularly challenging chemical reactions.
"We have shown, for the first time ever, that it is possible to effectively create a carbon-iron bond using a safe and cheap catalyst based on potassium instead of the rare and expensive metals such as platinum, palladium and iridium," said Anton Toutov, the researcher who conducted these experiments. "We are very excited about the discovery of the new method not only due to the fact that it is "greener" and more efficient, but also because it is thousands of meters cheaper than the accepted methods today. This is a technology that the chemical industry could easily adopt.”
The findings mark one of the first cases in which catalysis - the use of catalysts to speed up chemical reactions - deviates from the usual use of non-sustainable materials; While the precious metals used in most common catalysts are rare and may become scarce in the future, potassium is a very common element on Earth. The researchers presented the findings of their innovative "green" chemical process in the prestigious journal Nature.
Researcher Brian Stoltz, a professor of chemistry at the institute, says that other researchers were very surprised by these findings because, although the chemistry behind the catalyst is very complex and challenging, the catalyst itself - potassium tert-butoxide - seems remarkably simple. The white powder, which looks similar to table salt, provides a simple and environmentally friendly way to perform a reaction in which a carbon-hydrogen chemical bond is converted to a carbon-iron chemical bond in order to create molecules known as organo-silanes. These organic molecules are of great interest since they are used as chemical building blocks especially important in the field of medicinal chemistry leading to the development of new drugs. They also hold the promise for the development of new materials to be used in products such as LCD screens and organic solar cells, in the development of new and more effective pesticides and in the development of new materials for medical imaging. "The ability to successfully carry out this reaction, which is one of the most studied reactions in the world of chemistry, with the help of a simple substance like potassium tert-butoxide - a substance that is not based on a precious metal but still functions as a catalyst - was a complete surprise for us," says the researcher.
The current research began several years ago when co-researcher Alexey Fedorov dealt with a completely different subject - he tried to break the carbon-oxygen bonds in biomass using simple iron compounds, metals and the substance potassium tert-butoxide known as a profit additive. During this study he conducted a control experiment in which he removed the metal but left the additive. Much to his surprise - the reaction still happened. The researchers found that in addition to obtaining the expected products from this reaction, a small amount of organosilanes was obtained. This finding was particularly surprising in light of the fact that the production of these materials (organo-silanes) is particularly challenging. "I thought this finding was impossible, so I went back again and checked this reaction several times," explains the researcher. "It turns out that the reaction did happen!" The researchers continued to fine tune the reaction conditions so that in the end they were able to create the only organosilane they desired in high utilization under mild conditions while obtaining hydrogen gas as the only byproduct.
In the next step, the researchers were able to create a whole group of such substances that are common in the chemical and pharmaceutical industries. The surprise of the researchers even led them to check if there were tiny amounts of metals in the reagents that were not normally observed. They found out not. "We synthesized the potassium tert-butoxide substance ourselves and also purchased it from a number of different suppliers, and still the result remains the same. Until now, researchers have not yet been able to understand why this simple catalyst is able to carry out these complex reactions. The researchers are collaborating with other research groups in the field of chemistry to answer this question. "It is quite clear that the substance works in a mechanism that is completely different from the mechanism in which the precious metals work," notes the lead researcher. The researcher adds and points out that unlike other catalysts that stop working or become sensitive to air/water when the reactions become large/industrial, the new catalyst seems to be stable enough to be used in industry. In order to demonstrate the material's great value to industry, the team used the new method to prepare almost 150 grams of valuable organo-silane - the largest amount of this product prepared in a single catalytic reaction. The reaction required no solvent at all, produced hydrogen gas as the only by-product and occurred at a temperature of 45 degrees Celsius – the lowest temperature known in the literature so far at which this reaction was able to occur.
One response
My understanding of these areas is not something but the article is clear and clear and especially its implications.
Thanks!