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 Kidney tumor: Genetic trigger discovered
19.06.2018 | Julius-Maximilians-Universität Würzburg

nachricht New type of photosynthesis discovered
18.06.2018 | Imperial College London

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Novel method for investigating pore geometry in rocks

18.06.2018 | Earth Sciences

Diamond watch components

18.06.2018 | Process Engineering

New type of photosynthesis discovered

18.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>