Germyl linker cleavage with carbon-based electrophiles
This thesis describes the successful identification of a novel cross-coupling protocol for alkylaryldichlorogermanes, as part of an investigation towards the development of organogermanium linkers for solid phase synthesis. The application of Friedel-Crafts acylation towards the ipso degermylation of aromatic molecules with concomitant introduction of acyl functionality is also described. By way of introduction, an in depth review of the literature surrounding Group 14 organometallic cross-couplings is presented, concentrating on the recent developments in the area of organosilicon and organogermanium cross-coupling chemistry. This is followed by a review of the literature precedent for ipso acyldesilylation and acyldestannylation of aromatic molecules. Results are then presented that detail the work carried out towards successful arylgermane cross-coupling. Following extensive study and attempted optimisation of trialkylarylgermane cross-couplings, it was discovered that the incorporation of heteroatoms onto the germanium centre was necessary to obtain synthetically acceptable cross-coupling yields. Further results are also presented In relation to acyldegermylation studies that illustrate the reactivity of arylgermanes towards acyl electrophiles, and the effect on acyldegermylation of varying the electronic nature of the aryl group attached to germanium.