“Constrained geometry” catalysts of the rare-earth metals for the hydrosilylation of olefins

A series of yttrium and lutetium alkyl complexes [Ln(η5-C5Me4ZNR′-κN)(CH2SiMe3)(THF)n] (Ln = Y, Lu) was prepared by reacting the tris(trimethylsilylmethyl) precursor [Ln(CH2SiMe3)3(THF)2] with different linked amino-cyclopentadienes of the type (C5Me4H)ZNHR′ (Z = SiMe2, CH2SiMe2; R′ = tBu, Ph, C6H4-tBu-4, C6H4-nBu-4). The catalytic activity of these alkyl complexes in the hydrosilylation of 1-decene and styrene using PhSiH3 as reagent was examined under standard conditions. A significant influence of the ligand structure on the catalytic property (turnover frequency, regioselectivity) was observed with the yttrium complex [Y(η5-C5Me4CH2SiMe2NtBu-κN)(CH2SiMe3)(THF)] being the most active for 1-decene hydrosilylation.