How Can We Discover More Chemical Reactions? — Chromatography Explores

Finding new chemical reactions can be a laborious process — but it is an important process that could lead to novel products and large cost savings. Often the process means working on paper using hundreds, if not thousands, of reactions that have been previously carried out to see what small changes might bring about.

But with thousands of molecules to use and many different catalysts that can be used, the process is costly and time consuming. In a paper in the journal Science — Snap deconvolution: An informatics approach to high-throughput discovery of catalytic reactions — chemists from the University of California, Berkeley suggest a method they have called snap deconvolution could help to speed up the process.

Finding needles in haystacks

Chemists searching for new materials or methods react compounds from a library of compounds two at a time — typically with a catalyst — and then screen the results for new compounds using gas chromatography mass spectrometry to identify the products. The use of chromatography to screen for components is discussed in the article, Rapid Screening of Volatile and Semi-Volatile Organic Components in Cocoa Beans and Chocolate Products Using a Portable GC/MS System.

This is the approach that was used by the chemists at Berkeley but they have managed to speed the process up using better data analysis — allowing them to screen three times as many reactions each day. And it involves a simple manipulation of the starting masses of the reactants.

Rehash of an ‘old’ idea

The process that John Hartwig and his postdoc Konstantin Troshin is based on a process that Hartwig first used in 2011 to provide a shortcut to the screening process. That process involved reacting the starting molecules together with different catalysts and conditions. The products were then screened using GC-MS.

The basic idea was that if you know the masses of the reactants, by measuring the masses of the products you can tell what reactions had taken place. However, if the reactants had similar masses it was difficult to analyse what reactions had taken place. The method has advantages over other screening methods in that there are no fluorescent labels — these are typically used to follow molecules through reactions.

The new method involved filling a tray of wells up with reactants using different types and quantities of catalysts — metal ligands.  — before heating the tray to 100ËšC for several hours. But the reactants were modified to help the team spot new reactions. They added inert substituents to the reactants whose mass was known. This made the subsequent analysis after GC-MS mush quicker.

Besides the team finding that the analysis was quicker, they also found new reactions. Other chemists are excited about the new method and its possibilities.