Generation of ditetrelynes by B-O bond elimation: bond activation and catalysis

This project will investigate the formation of low-valent group 14 compounds under catalyticaly relevant conditions via the formation of strong E'-O bonds (E' = B, Al, Si). These ditetrelynes will then be investigated for their reductive bond activation capacity towards a range of organic and inorganic substrates and subsequently applied in catalytic transformations.

Stage 1:
The project will initially focus on the formation of a range of terphenyl supported divalent group 14 alkoxides which will act as precatalysts. With these species in hand their reactivity towards E'-E' species will be targeted to generate species of the form LEEL (E = Ge, Sn; L = terphenyl) which contain E(I) centres.

Stage 2:
The reactivity of LEEL species (E = Ge, Sn; L = terphenyl) towards organic substrates containing reducible fragments such as heterocumulenes, alkenes, carbonyl derivatives; small molecules such as H2, CO, ethene and inorganic molecules such as phosphine oxides, tetravalent tetrels and isosteric, isoelectronic alkene analogues such as ammonia borane derivates will be investigated.

Stage 3:
With validated reductive steps and new methodologies to reform LEEL species under catalytically relevant conditions in hand, we will investigate the catalytic borylative reduction of the aforementioned substrates. Mechanistic insight will be sought via standard physical inorganic techniques, as well as operando spectroscopy.

This work will seek to validate the efficacy of low valent main group fragments in redox cycling for catalysis. Such a mechanistic approach would be unique and is one of the "holy grails" of main group chemistry today. The implications for the uptake of Earth abundant and green catalysis would be profound by replacing precious metal catalysis. This will contribute to Britain's world leading position in fine chemicals. This work fits within the EPSRC's ongoing interest in catalysis.

Dr Ruth Webster will act as second supervisor as a result of her extensive experience in the area of Earth abundant metal catalysis and she will provide input on mechanistic insight, new reaction development and in situ analysis of reactivity.