| Summary: | <p>We report our investigations into the first examples of copper-free 1,3-dipolar cycloaddition (click) reactions of electrophiles with a Pt<small><sup>IV</sup></small> azido complex. The Pt-<small><sup>IV</sup></small> azido complex <em>trans</em>, <em>trans</em>, <em>trans</em>-[Pt<small><sup>IV</sup></small>(py)<small><sub>2</sub></small>(N<small><sub>3</sub></small>)<small><sub>2</sub></small>(OH)<small><sub>2</sub></small>] (<strong>1</strong>) was reactive towards dimethyl acetylenedicarboxylate (DMAD) (<strong>2</strong>), diethyl acetylenedicarboxylate DEACD (<strong>3</strong>), <em>N</em>-[(1<em>R</em>,8<em>S</em>,9<em>s</em>)-bicyclo[6.1.0]non-4-yn-9-ylmethyloxycarbonyl]-1,8-diamino-3,6-dioxaoctane (BCN) (<strong>11</strong>) and dibenzocyclooctyne-amine (DBCO) (<strong>12</strong>) resulting in formation of the corresponding mono (a) and bis-substituted (b) complexes. Complexes of <strong>2</strong> undergo further reactions between the Pt centre and the carbonyl group to form <strong>2a′</strong> and <strong>2b′</strong>. This is not seen for the products of the corresponding Pt<small><sup>II</sup></small> azido complex <em>trans</em>-[Pt(py)<small><sub>2</sub></small>(N<small><sub>3</sub></small>)<small><sub>2</sub></small>] with acetylene <strong>2</strong>. Novel complexes <strong>2a′</strong>, <strong>2b′</strong>, <strong>11a</strong> and <strong>11b</strong> have been characterised by multinuclear NMR, IR and UV-vis spectroscopy and ESI-MS. These reactions represent new synthetic routes to novel Pt(<small>IV</small>) complexes.</p>
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