New Routes to η¹- and (η³↔η⁵)-Indenylpalladium\nComplexes: Synthesis, Characterization, and Reactivities

Abstract

The dimer {(η³-Ind)Pd(μ-Cl)}₂ (<b>6</b>) reacts with <i>t</i>-BuNC to give the dimeric species {(η¹-Ind)(<i>t</i>-BuNC)Pd(μ-Cl)}₂ (<b>10</b>), whereas reaction with PR₃ gives the complexes (η-Ind)Pd(PR₃)Cl\n(R = Ph (<b>4</b>), Cy (<b>7</b>), Me (<b>8</b>), OMe (<b>9</b>)). Complexes <b>4</b> and (1-Me-Ind)Pd(PPh₃)Cl (<b>5</b>) can also be\nprepared by reacting (PhCN)₂PdCl₂ with LiInd and PPh₃. The structural characterization\nof complexes <b>4</b>−<b>7</b>, <b>9</b>, and <b>10</b> by ¹H and ¹³C NMR spectroscopy and single-crystal X-ray\ndiffraction studies has allowed an analysis of the indenyl ligand's mode of coordination, both\nin the solid-state and in solution. Compounds <b>4</b>, <b>6</b>, and <b>7</b> react with PhSiH₃ in the absence\nof cocatalysts, whereas reaction with ethylene requires the presence of excess MAO to give\npolyethylene.