Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Catalysis: Putting cyanide to work

11.10.2012
Industrial-scale chemistry could benefit from a robust new catalyst that selectively generates amino acid precursors from cyanide at room temperature

Cyanide exposure can be lethal, but with careful handling, the molecule can be a very useful chemical building block. For example, from cyanide chemists can make life-essential amino acids that are in great demand as food additives and components in pharmaceutical production.


The self-supporting catalyst (top) is covered with tiny chiral pockets, within which simple starting materials (bottom, left) are converted into chiral amino acid precursors (bottom, right). © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim (top image)

The key step in this process is called the asymmetric Strecker reaction. Until now, this reaction has needed complex and costly catalysts, restricting its use to small-scale laboratory research. A new Strecker catalyst more amenable to scale-up is now available, thanks to Abdul Seayad, Balamurugan Ramalingam and their co-workers at the A*STAR Institute of Chemical and Engineering Sciences in Singapore. The catalyst also offers a safer way to handle the cyanide.

Seayad and Ramalingam made their Strecker catalyst from an inexpensive material based on titanium. It is called the self-supported chiral titanium cluster (SCTC). When warmed in the presence of water, the SCTC precursor assembles into robust solid clusters (see image). The key to its performance in the Strecker reaction is that the surface of each cluster is covered in tiny asymmetric “chiral pockets”, says Seayad. The reactions take place in these pockets, generating molecules that are a trivial chemical step away from amino acids.

Amino acids are chiral: they can exist in either of two mirror-image forms called enantiomers. For many applications — such as pharmaceutical production — chemists need a pure supply of only one enantiomer. Seayad and Ramalingam found that SCTC’s chiral pockets very selectively produce one enantiomer over the other, with a purity — or ‘enantiomeric excess’ — of up to 99%. Unlike previous catalysts, which required temperatures as low as -30 °C to operate effectively, the researchers achieved this selectivity at room temperature.

Stability is a further advantage of SCTC. The catalyst is impervious to air or moisture, and remains stable to 300 °C, making it well suited to use in a continuous flow reactor. The researchers could pack the catalyst into a cartridge and pump through the cyanide and other starting materials, generating amino acids in a steady stream. Safety is another key advantage, says Ramalingam. “Since only a limited amount of cyanide is present at the reaction zone at any point in time, any unforeseen situation can be easily handled,” he explains.

So far, the researchers have used an expensive reagent called TMSCN as their cyanide source. They are currently researching ways to generate SCTC in situ from inexpensive salts. “We will also evaluate the feasibility of up-scaling the reaction under flow conditions,” Seayad says.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Chemical and Engineering Sciences

References

Seayad, A. M., Ramalingam, B., Chai, C. L. L., Li, C., Garland, M. V. & Yoshinaga, K. Self-supported chiral titanium cluster (SCTC) as a robust catalyst for the asymmetric cyanation of imines under batch and continuous flow at room temperature. Chemistry – A European Journal 18, 5693–5700 (2012).

A*STAR Research | Research asia research news
Further information:
http://www.a-star.edu.sg
http://www.researchsea.com

More articles from Life Sciences:

nachricht Zap! Graphene is bad news for bacteria
23.05.2017 | Rice University

nachricht Discovery of an alga's 'dictionary of genes' could lead to advances in biofuels, medicine
23.05.2017 | University of California - Los Angeles

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

Scientists propose synestia, a new type of planetary object

23.05.2017 | Physics and Astronomy

Zap! Graphene is bad news for bacteria

23.05.2017 | Life Sciences

Medical gamma-ray camera is now palm-sized

23.05.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>