Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ruthenium in a Clinch

14.10.2008
Selectively and under mild conditions: primary amines from alcohols and ammonia with a ruthenium catalyst

Amines are needed for the production of pharmaceuticals, fine chemicals, agrochemicals, plastics, dyes, pigments, and additives. Most important are compounds with a terminal amino group (–NH2), known as primary amines. However, the selective synthesis of primary amines remains a challenge.

David Milstein and Chidambaram Gunanathan at the Weizmann Institute of Science (Israel) have now developed a new catalyst that allows the selective synthesis of primary amines directly from alcohols and ammonia under mild conditions. As they report in the journal Angewandte Chemie, their process involves a complex in which the central ruthenium ion is grasped by a ligand like a pincer.

The production of primary amines is so difficult because these products are very reactive and can thus continue to react to form secondary and tertiary amines as undesired byproducts. Previous methods of preparation also mostly require large amounts of toxic reagents. Most large-scale industrial processes are based on the reaction of alcohols with ammonia and require very high temperatures and pressures. This results in a mixture of amines, alkanes, and alkenes as byproducts. A selective catalytic synthesis of primary amines from alcohols and ammonia under mild conditions, without waste products, would be ecologically and economically beneficial.

The Israeli scientists have now developed a catalyst that fulfils these wishes: a novel, air-stable ruthenium complex. With two phosphorus-containing “arms”, an organic ligand grasps the ruthenium ion from two sides, holding it like a pincer. A third binding site for the metal ion is provided by a nitrogen atom in the ligand’s central aromatic ring system.

By using this pincer complex the researchers were able to selectively synthesize primary amines from alcohols and ammonia under mild conditions; large amounts of toxic compounds are not needed, and harmful waste is avoided. The reactions take place in toluene. Surprisingly, even alcohols immiscible in water react very well without solvents in the presence of water (“on water”).

This simple, generally applicable reaction delivers good yields of primary amines, and could represent an interesting alternative not only on the laboratory scale, but also on an industrial scale. In the synthesis of complex natural products and drugs, necessary amino groups could also be incorporated by means of this reaction step directly from the corresponding alcohols.

Author: David Milstein, Weizmann Institute of Science, Rehovot (Israel), http://www.weizmann.ac.il/Organic_Chemistry/milstein.shtml

Title: Selective Synthesis of Primary Amines Directly from Alcohols and Ammonia

Angewandte Chemie International Edition 2008, 47, No. 45, 8661–8664, doi: 10.1002/anie.200803229

David Milstein | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://www.weizmann.ac.il/Organic_Chemistry/milstein.shtml

More articles from Life Sciences:

nachricht Toward a 'smart' patch that automatically delivers insulin when needed
18.01.2017 | American Chemical Society

nachricht 127 at one blow...
18.01.2017 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

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...

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

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>