Wang, Cun Erker, Gerhard Kehr, Gerald Wedeking, Katrin Fröhlich, Roland Synthesis, Structural Features, and Formation of Organometallic Derivates of C<sub>1</sub>-Bridged Cp/Amido Titanium and Zirconium “CpCN-Constrained Geometry” Systems A series of C<sub>1</sub>-bridged Cp/amido group 4 metal complexes [(“CpCN”)MX<sub>2</sub>] was prepared. The starting compound 6-<i>tert</i>-butylfulvene (<b>7</b>) was reacted with LiNHR (R = <i>o</i>-anisyl (<b>a</b>), <i>p</i>-anisyl (<b>b</b>), phenyl (<b>c</b>), or <i>tert</i>-butyl (<b>d</b>)) to yield the Li(C<sub>5</sub>H<sub>4</sub>-CH(tBu)-NHR) compounds (<b>8</b>). Subsequent deprotonation with <i>n</i>-butyllithium, followed by transmetalation with Cl<sub>2</sub>Ti(NMe<sub>2</sub>)<sub>2</sub>, yielded the (“CpCN”)Ti(NR<sub>2</sub>)<sub>2</sub> complexes <b>10</b> (<b>a</b>−<b>d</b>). A second synthetic series started from 6-(dimethylamino)fulvene (<b>11</b>). The reaction with the LiNHR reagents led to addition followed by HNMe<sub>2</sub> elimination to yield the respective imino-substituted cyclopentadienides Li(C<sub>5</sub>H<sub>4</sub>-CHNR) (<b>13</b>). Addition of methyllithium to <b>13</b> gave the (Li<sup>+</sup>)<sub>2</sub>(C<sub>5</sub>H<sub>4</sub>-CHMe-NR)<sup>2-</sup>, (“CpCN”)<sup>2-</sup>, ligands (<b>14</b>). Transmetalation with Cl<sub>2</sub>Ti(NMe<sub>2</sub>)<sub>2</sub> subsequently yielded the corresponding μ-CHMe-bridged Cp/amido group 4 complexes <b>15</b> (<b>a</b>−<b>c</b>). Treatment with Me<sub>2</sub>SiCl<sub>2</sub> cleanly converted the (“CpCN”)M(NR<sub>2</sub>)<sub>2</sub> complexes to the respective (“CpCN”)MCl<sub>2</sub> systems [<b>3a</b>−<b>d</b>, <b>4a</b>−<b>c</b> (Ti), <b>5a</b> (Zr)]. These were transformed to the (“CpCN”)M(CH<sub>3</sub>)<sub>2</sub> complexes [μ-CHCMe<sub>3</sub>:  <b>17a</b>−<b>d</b> (Ti), <b>19a</b> (Zr), μ-CHMe:  <b>18a</b>−<b>c</b> (Ti)] and the (<i>s</i>-<i>cis</i>-supine-η<sup>4</sup>-butadiene)(“CpCN”)Ti systems <b>21a</b>−<b>d </b>and <b>22b</b>,<b>c</b>. With respect to X-ray structure analyses the (CpCN)MX<sub>2</sub> systems must be regarded as more “constrained” than their (“CpSiN”)MX<sub>2</sub> analogues. The (“CpCN”)MCl<sub>2</sub> and (“CpCN”)M(CH<sub>3</sub>)<sub>2</sub> complexes were used as catalysts for ethene homopolymerization and ethene/1-octene copolymerization. All systems gave active catalysts, but these were quite different in their catalytic performance when compared with the usually applied (“CpSiN”)TiX<sub>2</sub>-derived catalysts. The (“CpCN”)M catalyst activities and selectivities were very dependent on the specific activator components employed. 2 complexes 10;C 5 H 4;CpCN;CH;catalyst;C 1;Ti;2 complexes;HNMe 2 elimination;2 SiCl 2 2005-09-26
    https://acs.figshare.com/articles/dataset/Synthesis_Structural_Features_and_Formation_of_Organometallic_Derivates_of_C_sub_1_sub_Bridged_Cp_Amido_Titanium_and_Zirconium_CpCN_Constrained_Geometry_Systems/3266680
10.1021/om0505918.s009