A Catalytic Method to Form Carbon–Carbon Bonds by Coupling Two Carbon–Fluorine Bonds.

Project Information

FLUOROCROSS

Grant agreement ID: 745806

DOI

10.3030/745806

Project closed

EC signature date 8 March 2017

Start date 8 January 2018

End date 7 January 2020

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 195 454,80

EU contribution

€ 195 454,80

Coordinated by

IMPERIAL COLLEGE OF SCIENCE TECHNOLOGY AND MEDICINE
United Kingdom

Periodic Reporting for period 1 - FLUOROCROSS (A Catalytic Method to Form Carbon–Carbon Bonds by Coupling Two Carbon–Fluorine Bonds.)

Reporting period: 2018-01-08 to 2020-01-07

Summary of the context and overall objectives of the project

The biaryl motif contains two benzene rings joined by a carbon–carbon bond and is an established chemical building block. In recent years, there has been keen interest in biaryls containing fluorine atoms. The combination of a rigid, potentially planar, biaryl group and electronegative fluorine atom(s) engenders key benefits to organic molecules designed for use in liquid crystal displays or as the active ingredient in pharmaceuticals or agrochemicals. Biaryls are typically synthesized by coupling of an organometallic reagent with an aryl halide, a synthetic method that resulted in the 2010 Nobel Prize in chemistry. Despite wide-spread adoption of this approach, only recently have catalysts been developed that allow the cross-coupling of organometallics with carbon–fluorine bonds; most methods rely on the use of substrates containing weaker carbon–bromine or carbon–iodine bonds.

The direct coupling of two different fluorinated substrates by a reaction which breaks two carbon–fluorine bonds is unknown. If such a reaction could be developed it would open up the use of inexpensive fluorocarbons in synthesis.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In this project we took important steps toward achieving this goal. The main output was the development of a new catalytic reaction that transforms C-F bonds into C-Al bonds. The products of this reaction are useful partners in cross-coupling methodology allowing the synthesis of partially fluorinated biaryls. As part of our studies we developed a deep mechanistic understanding of a series of catalytic transformations including those that transform C-X bonds into C-Al bonds. This includes new transformations that are relevant to the fluorochemicals industry (fluoroarenes) and biomass (furans, anisoles). These new catalytic transformations rely on [Pd---Al] based catalysts. We were able to calculate a series of viable mechanisms for each type of substrate. The advance in our understanding from this comprehensive study will be essential for the long-term development of the project.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

In combination the work describes the scope and mechanism of new catalytic reactions that break strong C–F bonds in fluoroarenes and C–O bonds in furans and anisoles. These new reactions are important, not only because they all access to reactive chemical building blocks from readily available and typically unreactive starting materials, but also because we have developed a deep understanding of the mechanism of how the catalysts work. This information will likely transcend individual catalysts and catalytic reactions and form a keystone for developments in the field.

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