Rosenthal’s Zirconocene

Linshoeft, Julian

doi:10.1055/s-0034-1379317

Cited by 12 publications

(17 citation statements)

References 10 publications

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“…Several reactions of group 4 metallocene bis(trimethylsilyl)acetylene complexes with alkynes as well as 1,3-butadiynes were described in detail and were summarized in several papers and reviews. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Regarding 1,3-butadiynes different complexation modes, cleavage and coupling reactions were found, giving complexes shown in Scheme 26. Scheme 26.…”

Section: Products Of Reactions With Diynesmentioning

confidence: 99%

“…[2] Additionally, there are well defined complexes, in which the coordinatively and electronically unsaturated complex fragments [Cp′ 2 M] are stabilized in Cp′ 2 M(L) n by well suited ligands L as for example in the complexes Cp 2 Ti(PMe 3 ) 2 introduced by Rausch and Alt et al [3] Cp 2 Ti[(P(OEt) 3 ] 2 [4] and the here described complexes Cp′ 2 M(L)(η 2 -btmsa), btmsa = bis(trimethylsilyl)acetylene, with or without L such as pyridine or THF. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] There exist several methods to prepare such bis(trimethylsilyl)acetylene complexes Cp′ 2 M(η 2 -Me 3 SiC 2 SiMe 3 ) as starting materials. As typical examples for the complexes with unsubstituted Cp ligands the compound Cp 2 Ti(η 2 -Me 3 SiC 2 SiMe 3 ) was firstly obtained in 1988 by the reduction of Cp 2 TiCl 2 with magnesium in the presence of Me 3 SiC≡CSiMe 3 in THF at room temperature, [24b] later in 1993 by the reduction of Cp 2 TiCl 2 with n-butyllithium in n-hexane and adding Me 3 SiC≡CSiMe 3 at -78°[ 24c] as well as in 2010 by the reaction of Cp 2 TiMe 2 with Me 3 SiC≡CSiMe 2 H at 60°C in n-hexane.…”

Section: Introductionmentioning

confidence: 99%

“…All these avantages are not only restricted to this zirconium complex but are described for other group 4 metallocene complexes with bis(trimethylsilyl)acetylene in several synthetic and catalytic reactions which are summarized in ths update in addition to former described reactions. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Not only in stoichiometric reactions but also in catalytic transformations were these advantages investigated. [26][27][28][29][30][31][32][33][34][35] In this update mostly new stoichiometric and catalytic reactions starting from 2013 are summarized, which were not mentioned in the last reviews.…”

Section: Introductionmentioning

confidence: 99%

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Recent Synthetic and Catalytic Applications of Group 4 Metallocene Bis(trimethylsilyl)acetylene Complexes

Rosenthal

2019

Eur J Inorg Chem

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With the 30 years old first example of a stable group 4 metallocene bis(trimethylsilyl)acetylene (btmsa) complex Cp2Ti(η2‐btmsa) a series of similar complexes like Cp′2M(η2‐btmsa) (M = Ti, Zr; Cp′ = Cp, Cp* as η5‐pentamethylcyclopentadienyl and Cp′2 = rac‐(ebthi) as rac‐1,2‐ethylene‐1,1′‐bis(η5‐tetrahydroindenyl) ) represent excellent sources for the generation of the very reactive coordinatively and electronically unsaturated complex fragments [Cp'2M], which were used in many synthetic and catalytic reactions. Examples for this were oresented in several papers and summarized in some reviews. In this update new reactions of group 4 metallocene bis(trimethylsilyl)acetylene complexes towards symmetrically and unsymmetrically α‐dihetero‐substituted alkynes, reactions with other alkynes, di‐ and polyynes to metallacyclopentadienes as well as the conversions of the formed products are summarized. Additionally, novel synthetic applications of the formed metallacyclopentadienes on the basis of the zirconocene bis(trimethylsilyl)acetylene complex Cp2Zr(py)(η2‐btmsa) are highlighted. Reactions with imines, neutral N‐donor ligands, E‐H compounds (E = N, O, P), molecular hydrogen, water, phosphino‐ and aminoboranes, E‐Cl compounds (E = C, P), disilylated germylenes and aryloxy ketones were described. Different self‐assembly reactions to multinuclear complexes by using group 4 metallocene bis(trimethylsilyl)acetylene complexes in C‐C coupling reactions with or without C‐H bond activation to tri‐ or tetranuclear complexes are considered, too. These examples are discussed following the general L‐M‐S principle for stoichiometric and catalytic reactions, whereby different ligands L (L = Cp′ = Cp, Cp*, rac‐ebthi), metals M (M = Ti, Zr, Hf) and substrate substituents S influence the reactivity and the obtained products.

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Section: Products Of Reactions With Diynesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Recent Synthetic and Catalytic Applications of Group 4 Metallocene Bis(trimethylsilyl)acetylene Complexes

Rosenthal

2019

Eur J Inorg Chem

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“…The formation of the zirconium-intermediates was carried out by the reaction of the precursors 26 or 27 with Rosenthal´s zirconocene 34 [55][56] in toluene at 20 °C for 18 h (Scheme 3). 57…”

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confidence: 99%

Tuning the Optoelectronic Properties of Stannoles by the Judicious Choice of the Organic Substituents

et al. 2018

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1 Stannoles are organometallic rings in which the heteroatom is involved in a form of conjugation that involves excited states (σ*-π*-conjugation). Only little is known about how the substituents on the tin atom or substituents on the stannole ring determine the optoelectronic properties of these heterocycles. In this work, this has been studied experimentally and theoretically. Calculations of optimized equilibrium geometries, energy gaps between the HOMOs and LUMOs, and of the absorption spectra of a wide range of compounds were performed. The computational data showed that the substituents on the tin atom influence the optoelectronic properties to a lower extent than the substituents in the 2-and 5-positions of the ring. These substituents in the plane of the stannole ring can also have a strong influence on the overall planarity of the structure, in which mesomeric effects can play a substantial role only if the structure is planar. Thus, only structures with a planar backbone are of interest in the context of tuning optoelectronic properties. These were selected for the experimental studies. Based on this information, a series of six novel stannoles was synthesized by formation of a zirconium intermediate and subsequent transmetalation to obtain the tin compound. The calculated electronic HOMO-LUMO gaps varied between 2.94 eV and 2.68 eV.The measured absorption maxima were located between 415 nm and 448 nm as compared to theoretically calculated values ranging from 447 nm (2.77 eV) to 482 nm (2.57 eV). In addition to these optical measurements, cyclic voltammetry data could be obtained, which show two reversible oxidation processes for three of six stannoles. With this study, it could be demonstrated how the judicious choice of substituents can lead to large and predictable bathochromic shifts in the absorption spectra. ASSOCIATED CONTENT Supporting InformationThe Supporting Information is available free of charge on the ACS Publications website. It includes experimental and analytical details, NMR spectra, cyclic voltammetry and absorption spectra (PDF), crystal structure information (CIF) and all computational data (TXT).

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“…Systems that are more prone to ligand substitution include those possessing neutral placeholder ligands such as Cp 2 Ti(PMe 3 ) 2 , Cp 2 Ti(P[OEt) 3 ] 2 , [Cp* 2 Ti(N 2 )] 2 N 2 and others like Cp 2 Ti(CO) 2 as well as alkyne complexes of the type Cp′ 2 M(L)(η 2 ‐btmsa) (btmsa=bis(trimethylsilyl)acetylene; with or without L, L=pyridine or THF) …”

Section: Introductionmentioning

confidence: 99%

Advantages of Group 4 Metallocene Bis(trimethylsilyl)acetylene Complexes as Metallocene Sources Towards Other Synthetically used Systems

Rosenthal

2019

ChemistryOpen

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Active species for synthetic and catalytic applications are formed from well defined complexes or mixtures of compounds. For group 4 metallocenes, three pathways for the formation of the reactive complex fragment [Cp′ 2 M] are known: (i) reductive mixtures and well defined complexes which are able to form the metallocene fragments either by (ii) addition or (iii) substitution reactions. In this account for each of theses systems (i)–(iii) a prominent example will be discussed in detail, (i) the Negishi reagent Cp 2 ZrCl 2 /n‐BuLi, (ii) bis(η 5 : η 1 ‐pentafulvene) complexes and (iii) metallocene bis(trimethylsilyl)acetylene complexes, to show the advantages and the disadvantages for each of these methods for synthetic applications. This account summarizes some main advantages of group 4 metallocene bis(trimethylsilyl)acetylene complexes as metallocene generating agents over other synthetically used systems. For each of the special purposes, all described systems have advantages as well as disadvantages. The aim of this overview is to help synthetic chemists in selecting the most effective system on the basis of [Cp′ 2 M] (M=Ti, Zr) for synthetic or catalytic puposes.

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Rosenthal’s Zirconocene

Abstract: This feature focuses on a reagent chosen by a postgraduate, highlighting the uses and preparation of the reagent in current research spotlight Rosenthal's Zirconocene

Cited by 12 publications

References 10 publications

Recent Synthetic and Catalytic Applications of Group 4 Metallocene Bis(trimethylsilyl)acetylene Complexes

Recent Synthetic and Catalytic Applications of Group 4 Metallocene Bis(trimethylsilyl)acetylene Complexes

Tuning the Optoelectronic Properties of Stannoles by the Judicious Choice of the Organic Substituents

Advantages of Group 4 Metallocene Bis(trimethylsilyl)acetylene Complexes as Metallocene Sources Towards Other Synthetically used Systems

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