Linking molecular components through amide bonds is one of the most important reactions in research and the chemical industry. In the journal Angewandte Chemie, scientists have now introduced a new type of reaction for making amide bonds. Called an ASHA ligation, this reaction is fast, efficient, works under mild aqueous conditions, and is broadly applicable.
Amide bonds are the bond between a carbonyl carbon (C=O) and an organic nitrogen atom. It is amide bonds that link individual amino acids together into proteins and bind monomers into polyamide plastics like perlon and nylon. Many life-saving medicines such as taxol, lipitor and penicillin, as well as agrochemicals, biological conjugates, natural substances, and other products contain amide bonds. In addition to the classical method of production—the reaction of an acid group (-COOH) with an amino group (-NH(2))—a variety of different reactions have been developed for the formation of amide bonds. However, many of them are not broadly applicable due to a lack of chemoselectivity. They also require specialized coupling agents. New types of reactions are in demand.
Nagoya University-based research team develops new highly efficient catalyst for breaking resistant chemical bonds, paving the way for easier recycling of plastic waste
What to do proteins and Kevlar have in common? Both feature long chain molecules that are strung together by amide bonds. These strong chemical bonds are also common to many other naturally occurring molecules as well as man-made pharmaceuticals and plastics. Although amide bonds can give great strength to plastics, when it comes to their recycling at a later point, the difficultly of breaking these bonds usually prevents recovery of useful products. Catalysts are widely used in chemistry to help speed up reactions, but breaking the kinds of amide bonds in plastics, such as nylon, and other materials requires harsh conditions and large amounts of energy.
Building on their previous work, a research team at Nagoya University recently developed a series of organometallic ruthenium catalysts to break down even the toughest amide bonds effectively under mild conditions.
"Our previous catalysts could hydrogenate most amide bonds, but the reactions needed a long time at high temperature and high pressure. This new ruthenium catalyst can hydrogenate difficult substrates under much milder conditions," says lead author Takashi Miura.
Hydrogenation is the key step leading to breakdown of amide bonds. The catalyst features a ruthenium atom supported in an organic framework. This ruthenium atom can adsorb hydrogen and deliver it to the amide bond to initiate the breakdown. The team probed the position of hydrogen on the catalyst in the reaction pathway and modified the shape of the supporting framework. By making sure that the hydrogen molecule was is the best possible position for interaction with amide bonds, the team achieved much more effective hydrogenation.
Group leader Susumu Saito says, "The changes we made to the catalyst allowed some tricky amide bonds to be selectively cleaved for the first time. This catalyst has great potential for making designer peptides for pharmaceutics and could also be used to recover materials from waste plastics to help realize an anthropogenic chemical carbon cycle."
The article, "Multifaceted catalytic hydrogenation of amides via diverse activation of a sterically confined bipyridine-ruthenium framework" was published in Scientific Reports at DOI: 10.1038/s41598-017-01645-z
PhD Studentship - E–mides – Amides as Versatile Building Blocks via Reductive Activation at The University of Manchester - (Jobs/Scholarships)
Title:Application deadline: 4th May 2026Research theme: Organic ChemistryHow to apply: https://uom.link/pgr-apply-2425 [uom.link]
This 3.5-year PhD studentship is open to Home (UK) and overseas students. The successful candidate will receive an annual tax-free stipend set at the UKRI rate (£21,805 for 2026/27; subject to annual uplift), and tuition fees will be paid. We expect the stipend to…
Stable and reusable nanoscale Fe2O3-catalyzed aerobic oxidation process for the selective synthesis of nitriles and primary amides
Stable and reusable nanoscale Fe2O3-catalyzed aerobic oxidation process for the selective synthesis of nitriles and primary amides Green Chem., 2018, Advance Article
DOI: 10.1039/C7GC02627G, Paper Kathiravan Murugesan, Thirusangumurugan Senthamarai, Manzar Sohail, Muhammad Sharif, Narayana V. Kalevaru, Rajenahally V. Jagadeesh
Nanoscale Fe2O3-catalyzed environmentally benign synthesis of…
Nickel-Catalyzed Decarbonylative Suzuki–Miyaura Coupling of Amides To Generate Biaryls
Nickel-Catalyzed Decarbonylative Suzuki–Miyaura Coupling of Amides To Generate Biaryls
Shi et al. have reported a nickel-catalyzed decarbonylative Suzuki–Miyaura reaction which uses an N-aroylpiperidine-2,6-dione as the coupling partner for the boronic acid ( Angew. Chem., Int. Ed. 2016, 55, 6959−6963). The method is attractive from the point of view of the stability of N-aroylpyrrolidine-2,5-diones toward storage and manipulation and the flexibility they add to the chemist’s…
Intravenous and oral formulations of acetylcysteine are available for the treatment of paracetamol (acetaminophen) overdose. In the treatment of acetaminophen overdose, acetylcysteine acts to maintain or replenish depleted glutathione reserves in the liver and enhance non-toxic metabolism of acetaminophen.
Mucolytic therapy
Inhaled acetylcysteine is indicated for mucolytic therapy as an adjuvant in respiratory conditions with excessive and/or thick mucus production. Such conditions include emphysema, bronchitis, tuberculosis, bronchiectasis, amyloidosis, pneumonia, cystic fibrosis, chronic obstructive pulmonary disease, pulmonary fibrosis, and inhalation injury in children who have burns. It is also used post-operatively, as a diagnostic aid, and in tracheotomy care.
Nephroprotective agent
Oral acetylcysteine is used for the prevention of radiocontrast-induced nephropathy (a form of acute kidney failure).
Hemorrhagic cystitis
Acetylcysteine has been used for cyclophosphamide-induced hemorrhagic cystitis, although mesna is generally preferred due to the ability of acetylcysteine to diminish the effectiveness of cyclophosphamide
Acetylcysteine is used in the treatment of interstitial lung disease to prevent disease progression
