om500087s_si_003.xyz (19 kB)
Zirconium and Hafnium Hydrazinediido Half-Sandwich Complexes: Synthesis and Reactivity
dataset
posted on 2014-04-14, 00:00 authored by Peter
D. Schweizer, Hubert Wadepohl, Lutz H. GadeThe hydrazinediido complexes [Cp*M(NxylN)(NNPh2)(dmap)] (M = Zr, 3a; M
= Hf, 3b; NxylN = 2-(N-xylylamino)pyrrolinate)
have been
synthesized, and their reactivity has been investigated. Both complexes
were prepared from [Cp*M(NxylN)Cl2] (1a,b) and [Cp*M(NxylN)(NHNPh2)Cl]
(2a,b), respectively, as precursors. While 3a was obtained by dehydrohalogenation of 2a using
LiHMDS in the presence of dmap, reaction of 2b with LiHMDS
initially afforded a mixture of [Cp*Hf(NxylN)(NHNPh2)2] (6) and [Cp*Hf(NxylN)(NNPh2)LiHMDS] (4), which was thermolyzed
subsequently in the presence of dmap to yield 3b. [Cp*Zr(NxylN)(NNPh2)(dmap)] (3a) reacted with
diisopropylcarbodiimide, giving the rearranged [2 + 2] cycloaddition
product [Cp*Zr(NXylN){κ2-NiPrC(NNPh2)NiPr}] (7) and the six-membered
zirconacycle [Cp*Zr(NXylN){κ2-N(NPh2)C(NiPr)NiPrC(NiPr)NiPr}] (8a). With N-phenylbenzimine
the cycloaddition product [Cp*Zr(NXylN){κ2-N(NPh2)CHPhNPh}] (9) was isolated, and upon
reaction with diphenylacetylene the seven-membered zirconacycle [Cp*Zr(NXylN){κ2-N(Ph)-o-phenylene-C(Ph)C(Ph)NH}]
(10) was obtained. Reaction of the previously synthesized
compound [Zr(N2TBSNpy)(NNPh2)py] (11) with iPrNCNiPr and with PhCHNPh gave the four-membered
zirconacycles [Zr(N2TBSNpy){κ2-N(NPh2)C(NiPr)NiPr}] (12) and [Zr(N2TBSNpy){κ2-N(NPh2)CHPhNPh}] (13), respectively.
