Wright, LJFrogley, Benjamin2017-05-162016http://hdl.handle.net/2292/32916Metalla-analogues of archetypical aromatic compounds have been attracting a great deal of interest in recent years. Metallabenzenes, where a methine unit in benzene has been formally replaced by a transition metal and its ancillary ligands, are a well-studied example which fall into this class. However, examples where additional fused rings are attached to the metallabenzene core are scarce and the chemistry of these `fused-ring metallabenzenes' is only just beginning to be explored. The work described herein sought to contribute to our understanding of these intriguing compounds. The focus was directed to two key areas. Firstly, the chemistry of fused-ring metallabenzenes was explored. We were especially interested in how the ligand environment about the metal could influence the reactions on the metallacyclic rings and the ring substituents. Secondly, rational syntheses of new fusedring metallabenzenes were designed and executed. The chemistry of these novel compounds was explored as well. An underlying theme throughout the work was determining how the properties and chemistry of the metallacyclic species compared to their organic analogues. The introduction begins with a brief overview of aromaticity in general and how the properties of metallabenzenes and metallabenzenoids meet this classification. This moves on to a description of the reported synthetic routes to fused-ring metallabenzenes and the reactions which they undergo. Chapter 2 describes electrophilic aromatic substitution reactions of iridabenzofurans, the metalla-analogue of benzo[b]furan. These compounds contained only one ring substituent, making them ideally suited for this purpose. Halogenation, nitration and thiocyanogenation reactions were conducted, and it was determined that the regioselectivity and extent of the reactions were determined by the ancillary ligands on iridium, the formal charge of the complexes, and the nature of the electrophile. Several of the new compounds prepared by SEAr reactions were well-suited for further reactions and this formed the basis for Chapter 3. The nitration products from the previous chapter served as precursors to the first metallabenzene derivatives with primary amino substituents. These could then be used to prepare simple derivatives such as alkylamines, sulfonamides, amides, as well as more unusual imide derivatives. The ancillary ligands and formal charge were again found to be important in determining the stability and extent of the reactions. The rst metallabenzene derivatives containing a ring of saturated carbons was described in Chapter 4. These were prepared by an extension of the synthesis used to prepare the iridabenzofurans. The additional five- or six-membered fused-rings bestowed these tricyclic iridabenzenes with an interesting new dimension to their chemistry. Bromination and dehydrobromination of the five-membered rings led to new iridaindene derivatives, while the same reactions with sixmembered rings gave dihydroiridanaphthalene derivatives. A further dehydrogenation of one of these allowed a metallanaphthofuran to be obtained. Extending the new procedure even further allowed the first metallaanthracene to be synthesised and this is described in Chapter 5. The iridaanthracene is the next member of the metalla-analogues of linear polycyclic aromatic hydrocarbons, for which only metallanaphthalenes were previously known. Structurally, it has a number of features in common with anthracene including fused-ring planarity and bond length alternation. In reactions which parallel those of anthracene, the iridaanthracene forms Diels-Alder adducts with dienophiles and on oxidation forms an unprecedented fused-ring metallaanthraquinone.Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher.https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htmhttp://creativecommons.org/licenses/by-nc-sa/3.0/nz/ThesisCopyright: The authorhttp://purl.org/eprint/accessRights/OpenAccessQ111963642