In order to meet future demands for new pharmaceuticals, innovative materials and agricultural pesticides, the chemical industry is dependent on the ongoing development of effective methods for the synthesis of complex organic compounds.
Because they are so versatile, organometallic molecules are of special significance in this context. Among these, reagents containing zinc atoms have certain advantages over the corresponding organolithium or -magnesium compounds, as they are compatible with a broader array of functional groups.
LMU chemists led by Professor Paul Knochel have now developed a simple “one-pot” method for the economical synthesis of organozinc pivalates. Up until now, such functionalized organozinc compounds were only available in liquid form, and were difficult to transport and store due to their susceptibility to degradation upon contact with air or moisture. The new synthetic route permits their formation as salt-stabilized solids, which can easily be recovered in powder form. “In this form, the reagents can be stored in an argon atmosphere for months without loss of activity,” says Knochel. “They can even be exposed to air for short periods without risk of degradation or ignition.” (Angewandte Chemie International Edition, early view, August 24, 2011)
One of the most prominent applications for organozinc reagents is their use for the so-called Negishi cross-coupling, a type of reaction that provides a simple means of linking carbon atoms together in a virtually unlimited variety of ways, and earned its discoverer a share of the Nobel Prize for Chemistry in 2010. “The new class of organozinc pivalates makes it possible to employ different solvents in the Negishi cross-coupling reaction and greatly extends the spectrum of coupling partners it can be applied to,” says Sebastian Bernhardt, who is the lead author on the new study. “The new reagents contain magnesium salts, which also facilitate the addition of organozinc pivalates to carbonyl groups.” This opens the way to their use for a whole series of applications relevant to the industrial manufacture of fine chemicals. The new scheme for synthesis of these compounds is the subject of an international patent application. (suwe/PH)Publication:
Scientists spin artificial silk from whey protein
24.01.2017 | Deutsches Elektronen-Synchrotron DESY
Choreographing the microRNA-target dance
24.01.2017 | UT Southwestern Medical Center
A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
24.01.2017 | Physics and Astronomy
24.01.2017 | Life Sciences
24.01.2017 | Health and Medicine