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Ruthenium complexes of phosphinocarboxamide ligands, and their use to form metallacycles using halide abstraction/deprotonation reactions are reported. Thus, [Ru(<i>p</i>-cym){PPh₂C(=O)NHR}Cl₂; R = <i>ⁱ</i>Pr (<b>1</b>), Ph (<b>2</b>), <i>p</i>-tol (<b>3</b>)] and [Ru(<i>p</i>-cym){PPh₂C(=O)N(R)C(=O)N(<i>H</i>)R}Cl₂; R = Ph (<b>4</b>), <i>p</i>-tol (<b>5</b>)] were synthesized from [(<i>p</i>-cym)RuCl₂]₂ (<i>p</i>-cym = <i>para</i>-cymene) and phosphinocarboxamides or phosphinodicarboxamides, respectively. Single-crystal X-ray diffraction measurements on <b>1</b>–<b>5</b> reveal coordination to ruthenium through the phosphorus donor, with an intramolecular hydrogen bond between the amine-bound proton and a metal-bound chloride. Six-membered metallacycles formed by halide abstraction/deprotonation of complexes <b>4</b> and <b>5</b> afforded [Ru(<i>p</i>-cym){<i>κ</i>²-<i>P,N</i>-PPh₂C(=O)N(R)C(=O)NR}Cl] [R = Ph (<b>6</b>), <i>p</i>-tol (<b>7</b>)]. These species exist as a mixture of two rotational isomers in solution, as demonstrated by NMR spectroscopy.