Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The more the merrier

16.03.2011
Computational search algorithms take the guesswork out of understanding complex, multi-molecule transformations

Multicomponent reactions (MCRs) that chemically combine three or more molecules into a brand new product are faster and generate less waste than traditional step-by-step synthetic procedures, making them invaluable in efforts to improve efficiency and sustainability.

Since 1921, chemists have used an MCR called the Passerini reaction to produce bioactive, peptide-like chains made from three partners: carboxylic acids, carbonyl compounds, and cyanide-bearing molecules. However, a full understanding of this process has eluded researchers because its multipart workings are difficult to detect experimentally.

Now, Satoshi Maeda and Keiji Morokuma from Kyoto University and Shinsuke Komagawa and Masanobu Uchiyama from the RIKEN Advanced Science Institute in Wako have developed a computerized way to better identify the hidden mechanisms of one-pot, multi-step chemical transformations[1]. Their technique, the artificial force induced reaction (AFIR), systematically squeezes and joins model compounds together in order to rapidly detect signatures of real MCR energy barriers.

According to Maeda, detailed theoretical understandings of MCRs have been scarce because most calculations require excellent estimates of transition state structures—intermediate and often highly strained geometric arrangements between molecules that correspond to the energetic peak of a reaction barrier. “Consequently, a trial-and-error process based only on [chemistry-based] intuition is unavoidable,” he says.

The AFIR method, on the other hand, requires no such presumptions. Maeda explains that when two molecules are pushed into each other with a weak force, they spontaneously relax into ‘dents’ in the potential barrier created by attractive electronic interactions between the reactants. By methodically pressing over all possible orientations, and inducing an artificial reaction from the relaxed positions, AFIR searches can identify every stable reaction pathway in a system.

To the team’s surprise, applying AFIR calculations to the Passerini reaction revealed that four components, not the long-thought three, must be involved (Fig. 1). Since the reaction barriers were so high, the researchers realized that an additional carboxylic acid—a known proton transfer catalyst—had to participate in the transition states leading to the final product. This finding should enable design of Passerini reactions with improved structural selectivity, notes Maeda.

Once perfected, the researchers anticipate their technique will make MCRs even more widespread. “Unlike standard methods, giving only pathways that are easy to find, the AFIR method has a unique ability to find unknown pathways in MCRs systematically,” says Maeda. “Information on reaction pathways is very important even for processes that do not normally occur, because chemists can initiate such reactions by controlling conditions, modifying substituents, and introducing new catalysts.”

Journal information

[1] Maeda, S., Komagawa, S., Uchiyama, M. & Morokuma, K. Finding reaction pathways for multicomponent reactions: The Passerini reaction is a four-component reaction. Angewandte Chemie International Edition 50, 644–649 (2011).

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton 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: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

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...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>