Synthese von 6,6,7,7,13,13,14,14‐Octamethyl‐6,7,13,14‐tetrasiladispiro[4.2.4.2]‐ tetradeca‐1,3,9,11‐tetraen und sein Einsatz in der π‐Komplexchemie von p‐ und d‐Block‐Elementen

Jutzi, Peter; Krallmann, R.; Wolf, Gerald; Neumann, Beate; Stammler, Hans‐Georg

doi:10.1002/cber.19911241103

Cited by 52 publications

(28 citation statements)

References 17 publications

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“…1,2-Bis(cyclopentadienyl)tetramethyldisilane [15] was synthesized according to lit- erature procedures and lithiated as described previously. [16] NMR spectra were recorded on a Bruker Avance 500 NMR Spectrometer at 500.…”

Section: Methodsmentioning

confidence: 99%

Intramolecular Activation of a Disila[2]molybdenocenophanedihydride: Synthesis and Structure of a [1],[1]Metalloarenophane

et al. 2008

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Metallocenophanes have attracted increasing attention in recent years, as strained ansa complexes have become pivotal precursors for organometallic polymers prepared by ringopening polymerization (ROP), whereas unstrained metallocenophanes, especially those derived from Group 4 metals, serve as catalysts for olefin polymerization.[1]The structural and electronic properties and the particular reactivity of ansa complexes are in the focus of current research. The reactivity of the EÀC ipso bond (E = bridging element, C ipso = ipso carbon atom of the cyclopentadienyl ring) is of major importance for ROP, which can be induced thermally, by interaction with nucleophiles, or by latetransition-metal catalysts.[1a-e] Furthermore, ligand exchange reactions, which play a role in catalytic processes, [1f-h, 2] as well as haptotropic shifts of cyclopentadienyl ligands under different conditions [3] are being intensely studied. [2]Metallocenophanes, which are not commonly susceptible to ROP owing to their lower molecular strain, nevertheless attracted considerable attention because of their pronounced propensity to oxidatively add to coordinatively unsaturated complexes of late-transition-metal elements through the bridging EÀE (E = B, Si, Sn) moiety. Owing to the facile activation of the E À E bond by, for example, Pd 0 and Pt 0 , subsequent insertions of various unsaturated organic substrates have been achieved. In 1992, Manners and coworkers reported the first Pd-catalyzed insertion of alkynes into the SiÀSi bridge of tetramethyldisila[2]ferrocenophane, [4] Herberhold et al. described in 1997 the first oxidative addition of a Pt 0 fragment into the SnÀSn bridge of an ansaferrocene and the subsequent insertion of an alkyne, [5] whereas our group accomplished oxidative additions of Pt 0 fragments as well as homogeneously and heterogeneously catalyzed insertions of alkynes and diazobenzene into BÀB and SiÀSi bonds of various [2]metalloarenophanes. [6] Motivated by this facile activation of the EÀE bridge, we wondered whether a corresponding oxidative addition can be achieved intramolecularly and turned our attention to tetramethyldisila[2]molybdenocenophanedihydride (1) as a promising starting material. Herein we report the synthesis and full characterization of this species and its conversion into an unprecedented twofold-bridged [1],[1]metalloarenophane.Compound 1 was synthesized by dilithiation of 1,2-bis(cyclopentadienyl)tetramethyldisilane in toluene/diethyl ether (9:1) at 0 8C and subsequent reaction with MoCl 5 at À78 8C in the presence of NaBH 4 as a reducing agent in THF/ hexane (4:1) (Scheme 1).The very air-sensitive but moisture-stable compound 1 was obtained as a yellow solid in 29 % yield and was characterized by multinuclear NMR spectroscopy in solution. Two characteristic virtual triplets for the C 5 H 4 ligands at d = 4.72 and 4.70 ppm, one singlet for the methyl groups at d = 0.17 ppm, and one signal for the hydrogen atoms at d = À8.20 ppm are observed in the 1 H NMR spectrum, thus indicating C 2v symmetr...

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Section: Methodsmentioning

confidence: 99%

Intramolecular Activation of a Disila[2]molybdenocenophanedihydride: Synthesis and Structure of a [1],[1]Metalloarenophane

et al. 2008

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“…197 A series of oligomers have been obtained from the palladium-catalysed reaction between Rc"(ZnCl) 2 and 1,8-diiodonaphthalene. In (22), obtained with a 1 : 1 ratio of reactants, the orientation of the Cp rings is rotated 42° from perpendicular to the C 10 plane, possibly as a result of charge repulsion on the face o f the Cp rings. 198…”

Section: Biruthenocenes and Highermentioning

confidence: 99%

Ruthenocenes and Osmocenes

Bruce

1995

Comprehensive Organometallic Chemistry II

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“…Compounds Li 2 [(Me 2 Si) 2 (C 5 H 4 ) 2 ] [46] and [NbCl 4 (thf) 2 ] [47] were prepared according to slightly modified literature procedures. NMR spectra were recorded on a Bruker Avance AV 500 or a Bruker Avance 200 NMR FT-IR spectrometer.…”

Section: General Considerationsmentioning

confidence: 99%