Synthesis, Structures, and Properties of the Phosphonium-1-indenylide (PHIN) Ligands 1-C<sub>9</sub>H<sub>6</sub>PPh<sub>3</sub>, 1-C<sub>9</sub>H<sub>6</sub>PMePh<sub>2</sub>, and 1-C<sub>9</sub>H<sub>6</sub>PMe<sub>2</sub>Ph and of the Corresponding Ruthenium(II) Complexes [Ru(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)(η<sup>5</sup>-PHIN)]PF<sub>6</sub>
作者:Kevin G. Fowler、Shalyn L. Littlefield、Michael C. Baird、Peter H. M. Budzelaar
DOI:10.1021/om200545j
日期:2011.11.28
Syntheses of the phosphonium-1-indenylide (PHIN) ligands triphenylphosphonium-1-indenylide (1-C9H6PPh3, I), methyldiphenylphosphonium-1-indenylide (1-C9H6PMePh2, II), and dimethylphenylphosphonium-1-indenylide (1-C9H6PMe2Ph, III) are reported, as are syntheses of the corresponding planar chiral ruthenium(H) complexes [Ru(eta(5)-C5H5)(eta(5)-1-C9H6PPh3)]PF6 (IV), [Ru(eta(5)-C5H5)(eta(5)-1-C9H6PMePh2)PF6 (V), and [Ru(eta(5)-C5H5)(eta(5)-1-C9H6PMe2Ph)PF6 (VI). The ruthenium complexes have been characterized by H-1, C-13, and P-31 NMR spectroscopy, by X-ray crystallography, and by extensive DFT calculations, which produce optimized geometries consistent with the crystallographic data. The PHIN Ru bond strengths are calculated to be similar to 20 kcal/mol greater than the corresponding benzene Ru bond strength of [Ru(eta(5)-C5H5)(eta(6)-C6H6)](+) and are compatible with the observed configurational stability of the complexes. That interconversion of enantiomers via interfacial exchange of the eta(5)-bound ligands does not occur is demonstrated by the observation of diastereotopic phenyl groups in the H-1 NAIR spectrum of V and of diastereotopic methyl groups in the H-1 NMR spectrum of VI.