Neutral Ru(η<sup>5</sup>-pyrrole) Complexes. Synthesis and Structure of Diazaruthenocenes and Ru(1-3:5,6-η<sup>5</sup>-C<sub>8</sub>H<sub>11</sub>)(η<sup>5</sup>-pyrrole) Complexes

The synthesis of metal complexes with anionic η<sup>5</sup>-pyrrole ligands is generally complicated by the free nitrogen lone pair. Methods are reported for the synthesis of two types of neutral η<sup>5</sup>-tetramethylpyrrolyl (NC<sub>4</sub>Me<sub>4</sub>) ruthenium complexes. Ru(η<sup>5</sup>-NC<sub>4</sub>Me<sub>4</sub>)<sub>2</sub> is prepared from (Ph<sub>3</sub>P)<sub>3</sub>RuCl<sub>2</sub> and lithium tetramethylpyrrolide in refluxing THF. A chiral diazaruthenocene with <i>C</i><sub>2</sub> symmetry is prepared from 2,3-dimethyl-4,5,6,7-tetrahydroindole. Attempts to prepare diazaruthenocenes from [Ru(η<sup>4</sup>-C<sub>8</sub>H<sub>12</sub>)Cl<sub>2</sub>]<i><sub>x</sub></i> led to deprotonation of the COD ligand to form a complex Ru(1-3:5,6-η<sup>5</sup>-C<sub>8</sub>H<sub>11</sub>)(η<sup>5</sup>-NC<sub>4</sub>Me<sub>4</sub>) isoelectronic with Ru(η<sup>5</sup>-NC<sub>4</sub>Me<sub>4</sub>)<sub>2</sub>.