Silyl‐Substituted ortho‐Terphenoxide Group 3–5 Complexes: Synthesis, Structure and Applications in Catalysis

Abstract The complexation behavior of 3,3’‐silyl‐substituted ortho ‐terphenoxide ligands o ‐C 6 H 4 (C 6 H 2 ‐2‐OH‐3‐SiR 3 ‐5‐Me) 2 (SiR 3 = SiPh 3 , SiMePh 2 , SiMe 3 , Si t ‐BuMe 2 ) with a range of yttrium, titanium, niobium and tantalum precursors was examined. The complexation of the ligands with [Y(N(SiHMe 2 ) 2 ) 3 (THF) 2 ] yielded monomeric complexes, as confirmed by NMR spectroscopy and X‐ray crystallography for the methyldiphenylsilyl‐ and tert ‐butyldimethylsilyl‐substituted complex. The triphenylsilyl‐substituted yttrium bis(dimethylsilyl)amido complex showed good activity in the intramolecular hydroamination reaction of aminoalkenes. Complexation with Ti(NMe 2 ) 4 yielded a mixture of products, depending on the silyl substituents and the solvent used for complexation. A mono‐ligated bimetallic titanium complex and a bisligated titanium complex were analyzed by X‐ray crystallography. Complexation with M(NMe 2 ) 5 (M=Nb, Ta) produced the corresponding monomeric ortho ‐terphenoxide complexes as confirmed by NMR spectroscopy and X‐ray structure analysis of a niobium complex and 3 tantalum complexes.