C−H and Si−N Bond Oxygenations of a Divalent Ytterbium Amide of the Pyrrolyl-Cyclopentadienyl Ligand

Hao, Jingjun; Song, Haibin; Cui, Chunming

doi:10.1021/om9004127

Cited by 19 publications

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References 39 publications

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“…The new cyclopentadiene with a neutral pendant pyrrolyl group C 4 H 2 Me 2 NSiMe 2 C 5 Me 4 H ( 1 ) was prepared in good yield by the reaction of C 5 Me 4 HSiMe 2 Cl with 2,5‐Me 2 C 4 H 2 NLi in THF at room temperature (Scheme ). Initially, it was envisaged to prepare ansa ‐sandwich scandium complexes, and anticipated they would display different reaction patterns by rendering versatile coordination modes of the neutral pendant pyrrolyl moiety to the central metal atom , . Acid‐base reaction of Sc(CH 2 C 6 H 4 NMe 2 ‐ o ) 3 with 1 equiv.…”

Section: Resultsmentioning

confidence: 99%

“…Initially, it was envisaged to prepare ansa-sandwich scandium complexes, and anticipated they would display different reaction patterns by rendering versatile coordination modes of the neutral pendant pyrrolyl moiety to the central metal atom. [28,29] Acid-base reaction of Sc(CH 2 C 6 H 4 NMe 2 -o) 3 with 1 equiv. of 1 in toluene at 70°C for 72 h, after workup, gave the half-sandwich scandium bis(aminobenzyl) complex (C 4 H 2 Me 2 NSiMe 2 C 5 Me 4 )Sc(CH 2 C 6 H 4 NMe 2 -o) 2 (2) in 75% isolated yield.…”

Section: Synthesis and Characterization Of Scandium Complexes Supportmentioning

confidence: 99%

“…To further investigate the structure‐reactivity of rare‐earth metal complexes, we extended our interest to rare‐earth metal complexes stabilized by pyrrolyl‐substituted cyclopentadienyl ligand. Employing such ligand, it was expected that the neutral pendant pyrrolyl moiety would render versatile coordination modes to central metal, and thus, would adjust reactivity patterns through tuning both Lewis acidity and effective coordination sphere at the central metal , . During the synthesis of scandium complexes bearing this ligand, it was found that acid‐base reaction of C 4 H 2 Me 2 NSiMe 2 C 5 Me 4 H with Sc(CH 2 C 6 H 4 NMe 2 ‐ o ) 3 and Sc[N(SiHMe 2 ) 2 ] 3 (THF) in 1:1 molar ratio gave the half‐sandwich scandium bis(aminobenzyl) complex (C 4 H 2 Me 2 NSiMe 2 C 5 Me 4 )Sc(CH 2 C 6 H 4 NMe 2 ‐ o ) 2 ( 2 ) and the scandium bis(silylamide) complex (C 4 Me 2 H 2 NSiMe 2 C 5 Me 4 )Sc[(NSiHMe 2 ) 2 SiMe 2 ](THF) ( 3 ), respectively.…”

Section: Introductionmentioning

confidence: 99%

“…was expected that the neutral pendant pyrrolyl moiety would render versatile coordination modes to central metal, and thus, would adjust reactivity patterns through tuning both Lewis acidity and effective coordination sphere at the central metal. [28,29] During the synthesis of scandium complexes bearing this ligand, it was found that acid-base reaction of C 4 H 2 Me 2 NSiMe 2 C 5 Me 4 H with Sc(CH 2 C 6 H 4 NMe 2 -o) 3 and Sc[N(SiHMe 2 ) 2 ] 3 (THF) in 1:1 molar ratio gave the half-sandwich scandium bis(aminobenzyl) complex (C 4 H 2 Me 2 NSiMe 2 C 5 Me 4 )Sc(CH 2 C 6 H 4 NMe 2 -o) 2 (2) and the scandium bis(silylamide) complex (C 4 Me 2 H 2 NSiMe 2 C 5 Me 4 ) Sc[(NSiHMe 2 ) 2 SiMe 2 ](THF) (3), respectively. Furthermore, both scandium complexes could serve as catalyst precursors for syndio-specific polymerization of styrene to give pure and highly syndio-tactic polystyrene (rrrrrr Ͼ 99 %).…”

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confidence: 99%

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Synthesis, Characterization, and Syndio‐Specific Styrene Polymerization of Pyrrolyl‐Substituted Cyclopentadienyl Scandium Complexes

Luo

Chen

2018

Zeitschrift anorg allge chemie

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Acid‐base reaction of Sc(CH2C6H4NMe2‐o)3 with 1 equiv. of pyrrolyl‐substituted cyclopentadienyl ligand C4H2Me2NSiMe2C5Me4H in toluene gave the half‐sandwich scandium bis(aminobenzyl) complex (C4H2Me2NSiMe2C5Me4)Sc(CH2C6H4NMe2‐o)2 (2). Amine elimination between Sc[N(SiHMe2)2]3(THF) and one equivalent of C4H2Me2NSiMe2C5Me4H afforded the scandium bis(silylamide) complex (C4Me2H2NSiMe2C5Me4)Sc[(NSiHMe2)2SiMe2](THF) (3). Both scandium complexes 2 and 3 were characterized by elemental analysis, NMR spectroscopy, and single‐crystal X‐ray diffraction. 2 and 3 could serve as highly active precursors for styrene polymerization to give syndio‐tactic polystyrene (rrrrrr > 99 %).

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Section: Resultsmentioning

confidence: 99%

Section: Synthesis and Characterization Of Scandium Complexes Supportmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

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Synthesis, Characterization, and Syndio‐Specific Styrene Polymerization of Pyrrolyl‐Substituted Cyclopentadienyl Scandium Complexes

Luo

Chen

2018

Zeitschrift anorg allge chemie

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“…[214] . 柄型吡咯基二价镱胺基配合物与分子氧发生分子内 C-H 和 Si-N 键氧化反应, 生成氧桥联的双核镱配合物 [215] . Arnold 等采用取代吡咯双齿配体合成了亚胺吡咯基稀土烷基配合物, 两个配体中的四个氮原子都以 η 1 模式与金属离子配位(图 41).…”

Section: β-二亚胺稀土金属有机配合物 β-二亚胺是最为重要的双齿配体unclassified

Sixty Years of the Chemistry of Rare-earth Organometallic Complexes

Changtao¹,

Wang²,

Chen³

2014

Acta Chim. Sinica

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Rare-earth elements include scandium, yttrium and fifteen lanthanides. Since Wilkinson and Birmingham reported the fist example of rare-earth organometallic complex, the chemistry of rare-earth organometallic complexes has had a great advance during the past sixty years. A variety of Cp containing rare-earth metal complexes, including mono-Cp, bis-Cp, and tri-Cp complexes, have been synthesized. Variation of the size of substituent on Cp ring, introducing the nitrogen or oxygen containing pendant arm to Cp ring or using ansa bis-Cp ligands make the synthesis and stabilization of these three types of rare-earth metal Cp complexes available. The Cp related ligands, such as indenyl and fluorenyl, also have been applied for the rare-earth organometallic complexes. From 1990's, there was a tendency to explore the rare-earth organometallic complexes with ancillary ligands beyond Cp and its derivatives in order to search for more efficient rare-earth metal catalysts. Non-Cp ligands, such as biphenolates, β-diketiminates, amidinates, guanidinates, etc. have been introduced into the chemistry of rare-earth organometallic complexes, and a larger number of non-Cp rare-earth organometallic complexes have been synthesized and characterized. The application of non-cyclopentadienyl ligands not only resulted in the rare-earth organometallic complexes with new structural features, but also the catalysts with high activity and high selectivity for the polymer synthesis and organic synthesis. The rare-earth organometallic complexes catalyze homo-and co-polymerization of olefins as well as specific polymerization of dienes and polar monomers. The discovery of the catalytic system composed of the neutral rare-earth metal dialkyls/borate enables to synthesize some interesting polymers which are difficult to be prepared by using other catalytic system. The rare-earth organometallic complexes are also able to catalyze some important organic reactions, such as hydroamination, hydrophosphinylation, and hydroalkoxylation, etc. Different from the late-translation metal catalyzed organic reactions, most of the rare-earth metal catalyzed ones do not involve oxidative addition and reductive elimination steps. The review describes some important developments of the chemistry of rare-earth organometallic complexes in the past sixty years.

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Syntheses, structures and catalytic activities of low‐coordinated rare‐earth metal complexes containing 2,2′‐pyridylpyrrolides

Zhou

Zhang

et al. 2019

Applied Organom Chemis

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Reactions of the ligand precursors 2‐(2′‐pyridyl)‐3,5‐Me2‐pyrrole (L1H) and 2‐(2‐pyridyl)‐3,4,5‐Me3‐pyrrole (L2H) with [(Me3Si)2N]3RE(μ‐Cl)Li(THF)3 in toluene afforded a series of low‐coordinated rare‐earth metal bis‐amido complexes L1RE[N(SiMe3)2]2 [RE = Y (1a), Dy (1b), Er (1c), Yb (1d)] and L2RE[N(SiMe3)2]2 [RE = Y (2a), Dy (2b), Er (2c), Yb (2d)]. With the ionic radius of rare‐earth metal increasing, the reaction of L1H and [(Me3Si)2N]3RE(μ‐Cl)Li(THF)3 gave dinuclear complexes (L1)2RE(μ‐Cl)(μ‐η5:η1:η1‐L1)RE(L1)[N(SiMe3)2]2 [RE = Sm (1e), Pr (1f)]; however, the reaction of L2H and [(Me3Si)2N]3Sm(μ‐Cl)Li(THF)3 afforded (L2)2Sm[N(SiMe3)2]2 (2e). Results indicated that the ionic radius of rare‐earth metal and subtle change in the ligands have substantial effects on the structure and bonding mode of complexes. The complexes showed a high catalytic activity for the ring‐opening reaction of cyclohexene oxide with amines to afford various β‐aminoalcohols under mild solvent‐free conditions.

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C−H and Si−N Bond Oxygenations of a Divalent Ytterbium Amide of the Pyrrolyl-Cyclopentadienyl Ligand

Cited by 19 publications

References 39 publications

Synthesis, Characterization, and Syndio‐Specific Styrene Polymerization of Pyrrolyl‐Substituted Cyclopentadienyl Scandium Complexes

Synthesis, Characterization, and Syndio‐Specific Styrene Polymerization of Pyrrolyl‐Substituted Cyclopentadienyl Scandium Complexes

Sixty Years of the Chemistry of Rare-earth Organometallic Complexes

Syntheses, structures and catalytic activities of low‐coordinated rare‐earth metal complexes containing 2,2′‐pyridylpyrrolides

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