An aluminum-based chemical reagent designed by a RIKEN scientist could prove to be a useful way of building complex carbon compounds, such as novel pharmaceuticals.
The aluminate reagent (i-Bu3Al(TMP)Li) is able to pluck a hydrogen atom away from a carbon atom to create a new carbon–aluminum bond. The aluminum can then be replaced by a wide variety of other chemical groups, allowing new compounds to be constructed.
Masanobu Uchiyama of RIKEN’s Advanced Science Institute in Wako, and colleagues at Tohuku University, Japan, and the University of Cambridge, UK, have now uncovered exactly how the aluminate reagent works, and for which reactions it is most suitable1.
Uchiyama and colleagues used density functional theory to calculate how chemical reactions involving the aluminum reagent were likely to proceed. This technique relies on quantum theory to determine how electrons are spread around the molecules involved in a reaction.
This revealed that it is specifically the ring-shaped TMP portion of the aluminate reagent that is responsible for removing a hydrogen atom at the beginning of the reaction; a conclusion confirmed by subsequent experiments.
The aluminate also requires only a single chemical step to remove the hydrogen atom from its target. But this process is markedly different when using an analogous zinc-based reagent investigated by the team.
By creating detailed computer models of both reagents caught in mid-reaction, the scientists found that their reaction pathways diverge because the aluminum atom is less able to attract electrons located on a nitrogen atom in a different part of the intermediate molecule.
The upshot is that while the zincate reagent tends to create the most energetically stable product molecule, the aluminate reagent simply replaces the most easily removed hydrogen atom, leading to a different end product.
Strong bases incorporating lithium or magnesium have been used traditionally for these reactions. But these reagents can inadvertently scramble part of the molecules involved in the reaction, and work only at very low temperatures.
Aluminates and zincates use much milder reaction conditions and are less likely to interfere with other parts of the reactant molecules, says Uchiyama. Choosing the appropriate reagent will give chemists the ability to control the course of chemical reactions that may have more than one possible product.
Knowing the precise path of the aluminate’s reaction should allow the scientists to improve the yields of compounds it generates, he adds. The team is now testing both reagents to assess how widely they can be used by chemists.
1. Naka, H., Morey, J.V., Haywood, J., Eisler, D.J., McPartlin, M., Garcia, F., Kudo, H., Kondo, Y., Uchiyama, M. & Wheatley, A.E.H. Mixed alkylamido aluminate as a kinetically controlled base. Journal of the American Chemical Society 130, 16193–16200 (2008).
The corresponding author for this highlight is based at the RIKEN Advanced Elements Chemistry Laboratory
‘Farming’ bacteria to boost growth in the oceans
24.10.2016 | Max-Planck-Institut für marine Mikrobiologie
Calcium Induces Chronic Lung Infections
24.10.2016 | Universität Basel
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
24.10.2016 | Earth Sciences
24.10.2016 | Life Sciences
24.10.2016 | Physics and Astronomy