Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

From Termite Fumigant to Molecular Coupling

01.09.2014

Sulfur fluoride exchange—a powerful new reaction for click chemistry

The coupling of molecular building blocks nearly as easy as “snapping” them together can be realized by means of the “click chemistry” tool kit. American scientists have now introduced another achievement for the click concept in the journal Angewandte Chemie: the sulfur fluoride exchange reaction (SuFEx) can be used to form robust inorganic bridges between carbon centers and opens up a fully unexplored area of chemistry with countless new molecules that could form the basis for new drugs, diagnostics, plastics, “intelligent” materials, and many other products.

Developed in the 1990s by Nobel Laureate K. Barry Sharpless and his colleagues, the concept of click chemistry is aimed at synthesizing target molecules rapidly and precisely from smaller units. The reactions must be specific, broadly applicable, and environmentally friendly while delivering high yields.

They must also be based on inexpensive, widely available reagents that react under mild and uncomplicated conditions. Since the discovery of the azide–alkyne cycloaddition reaction in 2002 by the Sharpless team, the click concept has become established as a universal chemical technique.

A team led by Sharpless at The Scripps Research Institute in La Jolla (CA, USA) has now developed another groundbreaking click reaction: sulfur fluoride exchange (SuFEx). This reaction exploits the very special reactivity of sulfur fluorides and makes it possible for chemists to bind together molecules of their choice.

Like most click reactions, the process itself is an old one that has been improved to allow the previously underestimated sulfate bond to be used as a universally applicable connector for linking a variety of molecular building blocks.

The starting material is a common, commercially available chemical called sulfuryl fluoride (SO2F2) that is widely used as a fumigant against termites and other pests. It was previously considered generally inert—incorrectly, as Sharpless and his co-workers have found. The team was able to make this chemical reactive in a reliable and predictable way.

In the SuFEx reaction, the fluoride ion must be extracted from a bond with a hexavalent sulfur atom. This is not so easy, so the SO2—F unit is remarkably stable in typical acidic or basic environments. This bond thus fulfills a central requirement of click chemistry: it remains “invisible” under most conditions, coming to life only on demand.

A broad palette of potential applications could benefit from this reaction. The teams of Sharpless and V. V. Fokin developed an efficient, nearly quantitative synthesis of high-molecular-weight polysulfate polymers that should be easy to implement on an industrial scale. Linked by sulfate groups, these polymers are sulfur-containing analogues of polycarbonates and represent a new class of plastics potentially superior to present-day materials.

One particular advantage is that unlike polycarbonates, which can react with water to give off bisphenol A—a substance that has hormonelike properties and poses problems for both health and the environment—polysulfates are resistant to hydrolysis and thus cannot release monomers.

This is just one application for the SuFEx reactions; many other reactions with other building blocks are possible. An advantage for the biological sciences is that sulfate links do not occur in any life forms and the new SuFEx reaction does not interfere with biological processes.

About the Author

K. Barry Sharpless, W. M. Keck Professor at The Scripps Research Institute and its Skaggs Institute for Chemical Biology, pursues and develops useful new chemical connectivity. Click chemistry was conceived by him in the mid-1990s as a method for rapidly discovering, and improving existing, useful reactivity. Now his group has found its 2nd 'perfect' click reaction. In 2001 he shared the Nobel Prize in Chemistry for his work on asymmetric catalysis.

Author: K. Barry Sharpless, The Scripps Research Institute, La Jolla (USA), http://www.scripps.edu/sharpless

Title: Sulfur(VI) Fluoride Exchange (SuFEx): Another Good Reaction for Click Chemistry

Angewandte Chemie International Edition 2014, 53, No. 35, 9430–9448, Permalink to the article: http://dx.doi.org/10.1002/anie.201309399

K. Barry Sharpless | Angewandte Chemie

Further reports about: Coupling Fumigant Molecular blocks conditions materials reactions reactivity sulfate sulfur

More articles from Life Sciences:

nachricht Lizard activity levels can help scientists predict environmental change
01.04.2015 | University of Missouri-Columbia

nachricht Climate change: bacteria play an important role in the long term storage of carbon in the ocean
01.04.2015 | Helmholtz-Zentrum für Umweltforschung - UFZ

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Lizard activity levels can help scientists predict environmental change

Research study provides new tools to assess warming temperatures

Spring is here and ectotherms, or animals dependent on external sources to raise their body temperature, are becoming more active. Recent studies have shown...

Im Focus: Hannover Messe 2015: Saving energy with smart façades

Glass-fronted office buildings are some of the biggest energy consumers, and regulating their temperature is a big job. Now a façade element developed by Fraunhofer researchers and designers for glass fronts is to reduce energy consumption by harnessing solar thermal energy. A demonstrator version will be on display at Hannover Messe.

In Germany, buildings account for almost 40 percent of all energy usage. Heating, cooling and ventilating homes, offices and public spaces is expensive – and...

Im Focus: Nonoxide ceramics open up new perspectives for the chemical and plant engineering

Outstanding chemical, thermal and tribological properties predestine silicon carbide for the production of ceramic components of high volume. A novel method now overcomes the procedural and technical limitations of conventional design methods for the production of components with large differences in wall thickness and demanding undercuts.

Extremely hard as diamond, shrinking-free manufacturing, resistance to chemicals, wear and temperatures up to 1300 °C: Silicon carbide (SiSiC) bundles all...

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

Skin tough

01.04.2015 | Materials Sciences

Methane monitoring method reveals high levels in Pennsylvania stream

01.04.2015 | Earth Sciences

Measurement of components in 3D under water

01.04.2015 | HANNOVER MESSE

VideoLinks
B2B-VideoLinks
More VideoLinks >>>