Mandal, Sutanuva Samanta, Subhas Mondal, Tapan K. Goswami, Sreebrata Comparative Study on <i>ortho</i>-C–H vs<i> ortho</i>-C–X (X = C, Cl, S) Bond Activation in <i>ortho</i>-C<sub>aromatic</sub>–N Bond Fusion in Substituted Anilines Using Ruthenium(II) Mediators: Isolation and Characterization of Unusual Ru<sub>2</sub> Complexes The chemical reactions of a selection of <i>ortho</i>-mono- and disubstituted anilines with two ruthenium polyene mediator complexes, CpRu<sup>II</sup>Cl­(PPh<sub>3</sub>)<sub>2</sub> (Cp<sup>–</sup> = cyclopentadienyl anion) and (Bnz)<sub>2</sub>Ru<sup>II</sup><sub>2</sub>Cl<sub>4</sub> (Bnz = benzene), have been undertaken with a primary aim to make a comparison between <i>ortho</i>-C–H and <i>ortho</i>-C–X (X = Cl, C, S) bond activation processes in <i>ortho</i>-C–N bond fusion reactions. The reaction of <i>ortho</i>-monosubstituted anilines, viz., 2-chloroaniline (HL<sup>1a</sup>), 2-methylaniline (HL<sup>1c</sup>), and 2-methylthioaniline (HL<sup>1b</sup>), with CpRu<sup>II</sup>Cl­(PPh<sub>3</sub>)<sub>2</sub> yielded mononuclear complexes [CpRu<sup>II</sup>L<sup>2a–c</sup>Cl] (<b>1</b>, <b>3</b>, and <b>5</b>), containing <i>in situ</i> generated ligands <i>N</i>-(aryl)-<i>ortho</i>-quinonediimine, L<sup>2a–c</sup>, along with anilido-bridged Ru<sup>III</sup><sub>2</sub> complexes (<b>2</b>, [CpClRu<sup>III</sup>{μ-η<sup>2</sup>-(L<sup>1a</sup>)<sup>−</sup>}]<sub>2</sub>; <b>4</b>, [CpClRu<sup>III</sup>{μ-η<sup>2</sup>-(L<sup>1c</sup>)<sup><b>–</b></sup>}]<sub>2</sub>; and [<b>6</b>]­Cl<sub>2</sub>, [CpRu<sup>III</sup>{μ-η<sup>2</sup>:η<sup>1</sup>-(L<sup>1b</sup>)<sup><b>–</b></sup>}]<sub>2</sub>), respectively. The new ligands, L<sup>2a–c</sup> are formed via<i> ortho</i>-C–H bond activation reactions, whereas <i>ortho</i>-C–X bonds remained unaffected. However, the <i>ortho</i>-C–Cl bond activation reaction is also noted in the reaction between CpRu<sup>II</sup>Cl­(PPh<sub>3</sub>)<sub>2</sub> and <i>ortho</i>-disubstituted aniline 2,6-dichloroaniline (HL<sup>3a</sup>) in more forceful conditions. The ruthenium­(III) binuclear complex [CpRu<sup>III</sup>{μ-η<sup>2</sup>:η<sup>1</sup>-(L<sup>3a</sup>)<sup><b>–</b></sup>}­(μ-η<sup>2</sup>:η<sup>1</sup>-L<sup>2d</sup>)­(μ-η<sup>2</sup>-acetate)­Ru<sup>III</sup>Cl]­Cl, [<b>7</b>]­Cl, of an <i>in situ</i> generated <i>N</i>-(2,6-dichlorophenyl)-6-chloro-<i>ortho</i>-quinonediimine ligand, L<sup>2d</sup>, has been isolated from the above reaction. The ligand L<sup>2d</sup> coordinates in a η<sup>2</sup>-binding mode through an imine (NH) nitrogen atom. The coordination mode of 2,6-dichloroanilide, (L<sup>3a</sup>)<sup><b>–</b></sup>, in [<b>7</b>]Cl is unusual in that an aromatic-C–Cl group is coordinated to a Ru­(III) center, and it represents the first authentic crystallographic evidence of such a coordination mode in a transition metal complex. Similar reactions on a redox-inert mediator complex, (Bnz)<sub>2</sub>Ru<sup>II</sup><sub>2</sub>Cl<sub>4</sub> (Bnz = benzene), with the aforesaid aromatic amines failed to result in <i>ortho</i>-C–N bond fusion reactions and afforded the mononuclear anilino complexes and an anilido-bridged Ru<sup>II</sup><sub>2</sub> compound, [<b>9</b>]­Cl<sub>2</sub>. The complexes have been characterized by using a host of physical methods as well as single-crystal X-ray structure determination. Their redox and spectroscopic properties have been thoroughly characterized by cyclic voltammetry and UV–vis and electron paramagnetic resonance spectroscopy. Density-functional theory calculations were employed to confirm their structural features and to support the spectral and redox properties. Bnz;ruthenium polyene mediator complexes;Cl;ligand L 2d coordinates;HL;Unusual Ru 2 ComplexesThe chemical reactions;NH;coordination mode;UV;bond activation processes 2012-08-13
    https://acs.figshare.com/articles/dataset/Comparative_Study_on_i_ortho_i_C_H_vs_i_ortho_i_C_X_X_C_Cl_S_Bond_Activation_in_i_ortho_i_C_sub_aromatic_sub_N_Bond_Fusion_in_Substituted_Anilines_Using_Ruthenium_II_Mediators_Isolation_and_Characterization_of_Unusual_Ru_sub_2_sub_Complexes/2497105
10.1021/om300241y.s003