Reactivity of Rare-Earth Metal Complexes Stabilized by an Anilido-Phosphinimine Ligand
writer：Bo Liu, Xinli Liu, Dongmei Cui and Li Liu
keywords：isoprene; phenylsilane; pincer; phenylacetylene; lutetium
source：期刊
specific source：http://pubs.acs.org/doi/pdf/10.1021/om801004r
Issue time：2008年
Treatment
of anilido-phosphinimine-ligated yttrium mono(alkyl) complex 1a,
LY(CH2Si(CH3)3)(THF) (L = o-(2,6-C6H3iPr2)NC6H4P(C6H4)(C6H5)N(2,4,6-C6H2Me3)),
with 2 equiv of phenylsilane in DME afforded methoxy-bridged complex 2,
[LY(μ-OCH3)]2, via the corresponding hydrido
intermediate. When excess isoprene was added to the mixture of 1a and
phenylsilane, a η3-isopentene product, 3, LY(CH2C(CH3)═CHCH3)(THF),
was isolated. A lutetium chloride, LLuCl(DME) (4), was generated through
the reaction of lutetium mono(alkyl) complex 1b, LLu(CH2Si(CH3)3)(THF),
with [Ph3C][B(C6F5)4]·LiCl
accompanied by the formation of [Li(DME)3]+[B(C6F5)4]?.
Metathesis reaction of 1b with excess AlMe3 at
room temperature gave a methyl-terminated counterpart, 5, LLu(CH3)(THF)2.
In all these reactions, the Ln?Cphenylbonds of complexes 1 remained
untouched. However, protonolysis of complex 1b with 2 equiv of
phenylacetylene in DME provided a lutetium bis(acetylide), LHLu(C≡CPh)2(DME)
(6), and the linkage of the Ln?Cphenyl bond was cleaved,
indicating that the activated C?H bond was recovered.
