Versatile reaction could help greenhouse gas become a more useful synthetic chemical
RIKEN chemists have developed a catalyst that should allow carbon dioxide to be used as a versatile synthetic chemical.
Carbon dioxide (CO2) is produced whenever fossil fuels are burned, and it is a powerful greenhouse gas that traps heat in our atmosphere, contributing to global warming. As such, turning the gas into a chemical feedstock, rather than allowing it to escape into the atmosphere, is an extremely appealing idea.
In fact, industry has long used carbon dioxide as a chemical building block—in the manufacture of the painkiller aspirin, for example—but its use is limited by the difficulty of breaking open its strong carbon-oxygen double bonds.
Carbon compounds activated by lithium or magnesium are often needed to attack and incorporate carbon dioxide successfully, but these reagents are extremely reactive and quite hazardous on a large scale.
Chemists have recently developed milder, boron-based alternatives, which require a rhodium catalyst to speed up the reaction. Unfortunately, this catalyst tends to break down particularly sensitive chemical groups in the product.
Zhaomin Hou, of RIKEN's Advanced Science Institute, Wako, along with colleagues Takeshi Ohishi and Masayoshi Nishiura, has now developed a copper catalyst that helps the boron compounds to react with carbon dioxide without destroying sensitive chemical groups.
This makes the reaction particularly useful for building complex molecules containing several different types of chemical group, something that would not be possible with the harsh lithium reagents. “We have tried many different metal compounds, among which the copper catalyst was the best,” says Hou.
The team was also able to study exactly how the catalyst works, by isolating key molecules at various intermediate stages of the reaction. They found that the active copper catalyst first displaces the boron group from the starting molecule, forming a new copper–carbon bond. Carbon dioxide then inserts itself into this bond before the copper catalyst is finally removed, leaving behind a carboxylic acid (-CO2H) group1.
Various forms of the boron compounds, known as boronic esters, are commercially available, says Hou. “And they can also be easily prepared in the lab.”
Hou adds that their method is also amenable to large-scale, commercial synthesis. “Since CO2 is a renewable carbon resource, exploration of new reactions and catalysts for its efficient use is of great importance,” he says. “One of our goals is to find a catalyst that can transform CO2 in exhaust gasses of automobile vehicles or chemical plants into useful materials.”
1. Ohishi, T., Nishiura, M. & Hou, Z. Carboxylation of organoboronic esters catalyzed by N-heterocyclic carbene copper(I) complexes. Angewandte Chemie International Edition 47, 5792–5795 (2008)
The corresponding author for this highlight is based at the RIKEN Organometallic Chemistry Laboratory
Tiny Helpers that Clean Cells
14.08.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
Light-controlled molecules: Scientists develop new recycling strategy
14.08.2018 | Humboldt-Universität zu Berlin
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.
Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...
If certain signaling cascades are misregulated, diseases like cancer, obesity and diabetes may occur. A mechanism recently discovered by scientists at the Leibniz- Forschungsinstitut für Molekulare Pharmakologie (FMP) in Berlin and at the University of Geneva has a crucial influence on such signaling cascades and may be an important key for the future development of therapies against these diseases. The results of the study have just been published in the prestigious scientific journal 'Molecular Cell'.
Cell growth and cell differentiation as well as the release and efficacy of hormones such as insulin depend on the presence of lipids. Lipids are small...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
14.08.2018 | Medical Engineering
14.08.2018 | Life Sciences
14.08.2018 | Life Sciences