Direct Synthesis of Titanium Complexes with Chelating cis ‐9,10‐Dihydrophenanthrenediamide Ligands through Sequential CC Bond‐Forming Reactions from o ‐Metalated Arylimines

A series of new titanium(IV) complexes with o ‐metalated arylimine and/or cis ‐9,10‐dihydrophenanthrenediamide ligands, [ o ‐C 6 H 4 (CHNR)TiCl 3 ] (R=2,6‐ i Pr 2 C 6 H 3 ( 3 a ), 2,6‐Me 2 C 6 H 3 ( 3 b ), t Bu ( 3 c )), [ cis ‐9,10‐PhenH 2 (NR) 2 TiCl 2 ] (PhenH 2 =9,10‐dihydrophenanthrene; R=2,6‐ i Pr 2 C 6 H 3 ( 4 a ), 2,6‐Me 2 C 6 H 3 ( 4 b ), t Bu ( 4 c )), [{ cis ‐9,10‐PhenH 2 (NR) 2 }{ o ‐C 6 H 4 (HCNR)}TiCl] (R=2,6‐ i Pr 2 C 6 H 3 ( 5 a ), 2,6‐Me 2 C 6 H 3 ( 5 b ), t Bu ( 5 c )), have been synthesised from the reactions of TiCl 4 with o ‐C 6 H 4 (CHNR)Li (R=2,6‐ i Pr 2 C 6 H 3 , 2,6‐Me 2 C 6 H 3 , t Bu). Complexes 4 and 5 were formed unexpectedly from the reactions of TiCl 4 with two or three equivalents of the corresponding o ‐C 6 H 4 (CHNR)Li followed by sequential intramolecular CC bond‐forming reductive elimination and oxidative coupling reactions. Attempts to isolate the intermediates, [{ o ‐C 6 H 4 (CHNR)} 2 TiCl 2 ] ( 2 ), were unsuccessful. All complexes were characterised by 1 H and 13 C NMR spectroscopy, and the molecular structures of 3 a , 4 a – c , 5 a , and 5 c were determined by X‐ray crystallography.