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 Cells migrate collectively by intermittent bursts of activity
30.09.2016 | Aalto University

nachricht The structure of the BinAB toxin revealed: one small step for Man, a major problem for mosquitoes!
30.09.2016 | CNRS (Délégation Paris Michel-Ange)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

Heavy construction machinery is the focus of Oak Ridge National Laboratory’s latest advance in additive manufacturing research. With industry partners and university students, ORNL researchers are designing and producing the world’s first 3D printed excavator, a prototype that will leverage large-scale AM technologies and explore the feasibility of printing with metal alloys.

Increasing the size and speed of metal-based 3D printing techniques, using low-cost alloys like steel and aluminum, could create new industrial applications...

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Paper – Panacea Green Infrastructure?

30.09.2016 | Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

 
Latest News

First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

30.09.2016 | Materials Sciences

New Technique for Finding Weakness in Earth’s Crust

30.09.2016 | Earth Sciences

Cells migrate collectively by intermittent bursts of activity

30.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>