Selective conversion of reactive lithium compounds made possible

Date:
August 12, 2020
Source:
Ruhr-University Bochum
Summary:
Researchers have developed a new catalyst that can catalyze
reactions to produce pharmaceuticals or chemicals used in
agriculture. It creates carbon-carbon bonds between what are
known as organolithium compounds without creating any unwanted
by-products.



FULL STORY ========================================================================== Researchers at Ruhr-Universita"t Bochum have developed a new catalyst
that can catalyse reactions to produce pharmaceuticals or chemicals used
in agriculture.

It creates carbon-carbon bonds between what are known as organolithium compounds without creating any unwanted by-products. The team led by
Professor Viktoria Da"schlein-Gessner, Inorganic Chemistry II Research
Group, describes the results in the journal Angewandte Chemie, published
online on 29 July 2020.


========================================================================== Indispensable for many applications Organolithium compounds are reagents
with a lithium-carbon bond, which are among the most reactive compounds
in synthetic chemistry. "Due to their special properties, they are indispensable in many applications, even on an industrial scale,"
says Viktoria Da"schlein-Gessner, member of the Cluster of Excellence
Ruhr Explores Solvation, Resolv for short. "However, high reactivity
often also leads to unwanted side reactions. As a result, organolithium compounds have so far only been considered to a limited extent, or even
not at all, for some applications." The research group led by Viktoria Da"schlein-Gessner was able to overcome such limitations with the help
of a highly efficient catalyst. The new phosphine- palladium catalyst selectively couples two carbon atoms -- both with different organolithium compounds and many so-called aryl halides. The decisive factor was that
it is sufficiently active, even at room temperature.

Market launch planned No additional additives are needed for the new
synthesis process and it can be used widely. This means that intermediate
steps during synthesis can be avoided, thus producing less metal salt
waste. The catalyst guarantees a high degree of selectivity, even if
product quantities of several grams are produced. To allow for use on an industrial scale, the next step must be to test it at even larger volumes.

In cooperation with industry, the researchers in Bochum intend to launch
the developed catalysts on the market soon. "Their particular activity
is not only advantageous in the described reactions, but also offers improvements for numerous other transformations in almost all areas
of fine chemical synthesis," says Da"schlein-Gessner. In addition to
the production of pharmaceuticals and chemicals for agriculture, these
include fragrances and materials for organic light-emitting diodes.


========================================================================== Story Source: Materials provided by Ruhr-University_Bochum. Original
written by Julia Weiler.

Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Viktoria H. Gessner, Thorsten Scherpf, Henning Steinert, Angela
Grossjohann, Katharina Dilchert, Jens Tappen, Ilja
Rodstein. Efficient Pd‐Catalyzed Direct Coupling of
Aryl Chlorides with Alkyllithium Reagents. Angewandte Chemie
International Edition, 2020; DOI: 10.1002/ anie.202008866 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200812144022.htm

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