Dimethylxanthene- and dibenzofuran-diamido complexes of titanium

Porter, Robin M.; Danopoulos, Andreas A.

doi:10.1016/j.poly.2005.09.011

Cited by 20 publications

(14 citation statements)

References 29 publications

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“…The synthetic accessibility of both 1a and 3 demonstrates the ability of the XN 2 ligand to accommodate both small and large metal ions, although this does not detract from the ability of 4,5-bis(anilido)xanthene dianions to function as rigid meridionally coordinating pincer ligands upon coordination to large rare-earth and actinide elements …”

Section: Resultsmentioning

confidence: 99%

Yttrium and Aluminum Alkyl Complexes of a Rigid Bis-Anilido NON-Donor Ligand: Synthesis and Hydroamination Catalysis

2017

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The palladium-catalyzed coupling of 4,5dibromo-2,7-di-tert-butyl-9,9-dimethylxanthene (XBr 2 ) with 2 equiv of 2,4,6-triisopropylaniline afforded the proligand 4,5bis(2,4,6-triisopropylanilino)-2,7-di-tert-butyl-9,9-dimethylxanthene (H 2 XN 2 ), and reaction of H 2 XN 2 with [Y-(CH 2 SiMe 2 R) 3 (THF) 2 ] (R = Me, Ph) produced the monoalkyl yttrium complexes [(XN 2 )Y(CH 2 SiMe 2 R)(THF)] (R = Me (1a), Ph (1b)). Neutral 1a showed near-zero ethylene polymerization activity (1 atm, 20 and 80 °C), and in the presence of AlMe 3 , 1a converted to [(XN 2 )Y{(μ-Me) 2 AlMe 2 }(THF)] (2). Compound 2 is thermally robust, and transfer of the XN 2 ligand from yttrium to aluminum was not observed even at elevated temperatures. However, [(XN 2 )AlMe] (3) was accessible via the reaction of H 2 XN 2 with AlMe 3 , demonstrating the ability of the wide-bite-angle XN 2 ligand to coordinate to much smaller aluminum(III). Neutral 1a proved to be highly active for both intra-and intermolecular hydroamination with various substrates, yielding Markovnikov products in the intermolecular hydroamination reactions with 1-octene. Article pubs.acs.org/Organometallics

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Section: Resultsmentioning

confidence: 99%

Yttrium and Aluminum Alkyl Complexes of a Rigid Bis-Anilido NON-Donor Ligand: Synthesis and Hydroamination Catalysis

2017

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“…However, by altering the design, Danopoulos and co‐workers found that a secondary aryl tether could force sterically bulky diamido ligands to adopt the planar mer isomer when installed on titanium (Figure 1). 8…”

Section: Introductionmentioning

confidence: 99%

Tethered Bis(amidate) and Bis(ureate) Supported Zirconium Precatalysts for the Intramolecular Hydroamination of Aminoalkenes

Lauzon¹,

Schafer²

2014

Zeitschrift anorg allge chemie

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“…Palladium-catalyzed coupling of 4,5-dibromo-2,7-di-tertbutyl-9,9-dimethylxanthene with 2 equivalents of 2,6-dimesitylaniline afforded 4,5-bis(2,6-dimesitylanilino)-2,7-di-tertbutyl-9,9-dimethylxanthene [H 2 (XAT); Scheme 1], which is an extremely sterically hindered analogue of the known 4,5-bis(2,6-diisopropylanilino)-2,7-di-tert-butyl-9,9-dimethylxanthene [12] and 4,5-bis(2,4,6-trimethylanilino)-2,7-di-tert-butyl-9,9-dimethylxanthene [13] pro-ligands. Reaction of H 2 (XAT) with excess KH in toluene yielded the dipotassium salt, and filtration and layering with hexanes at À30 8C deposited vibrant yellow X-ray quality crystals of [K 2 (XAT)(n-hexane)]·toluene (1; Scheme 1 and Figure 1).…”

Section: )]mentioning

confidence: 99%