Investigation into the uses of bimetallic alkyne complexes in organic synthesis

This thesis describes the use of both heterobimetallic and novel desymmetrised homobimetallic metal alkyne complexes in organic chemistry. A range of novel desymmetrised Co2(CO)5IPr-alkyne complexes have been synthesised and their reactivity investigated. This resulted in a highly diastereoselective thermal Pauson–Khand reaction. Previous protocols in the literature have had to use N-oxide promoters to achieve diastereoselectivity on desymmetrised bis-cobalt cores. The use of substituted dihydrofurans as cyclopropane surrogates for the formation of novel homobimetallic 1,3-dipoles has been realised, although currently with high substrate specificity. The zinc mediated addition of carbon nucleophiles to the inherently chiral Co(CO)3MoCp(CO)2-alkyne core has been investigated. This overcomes a previous lack of reactivity towards carbon nucleophiles, but expresses only low diastereoselectivity. The use of the Co(CO)3MoCp(CO)2-alkyne core as a nucleophilic chiral auxiliary has been thoroughly investigated. Chapter 1: an overview of the Pauson–Khand and Nicholas reaction and developments in the field. Chapter 2 highlights our research into the use of bimetallic-alkyne complexes in organic synthesis. Chapter 3 provides experimental data for our experiments.