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 Staying in Shape
16.08.2018 | Max-Planck-Institut für molekulare Zellbiologie und Genetik

nachricht Chips, light and coding moves the front line in beating bacteria
16.08.2018 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Staying in Shape

16.08.2018 | Life Sciences

Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter

16.08.2018 | Earth Sciences

Protein droplets keep neurons at the ready and immune system in balance

16.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>