Electron-deficient pentamethylcyclopentadienyl-1,3-butadiene complexes of titanium, zirconium, and hafnium

Blenkers, Joop.; Hessen, Bart; Bolhuis, F. Van; Wagner, A. J.; Teuben, Jan H.

doi:10.1021/om00146a005

Cited by 69 publications

(55 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reductive procedure is not successful for M = Ti, but Cp Ti(diene)Cl can be prepared by reaction of Cp TiCl 3 with (diene)Mg · 2THF [7,12]. Additionally, the butadiene ligand present in Cp M(1,3-butadiene)(1-methallyl) can be used to prepare Cp M(1,3-butadiene)Cl (and the 14 electron complexes Cp M(η 3 -1-methallyl)-Cl 2 ) by comproportionation with Cp MCl 3 [7].…”

Section: Synthesis and Derivatizationmentioning

confidence: 99%

“…Additionally, the butadiene ligand present in Cp M(1,3-butadiene)(1-methallyl) can be used to prepare Cp M(1,3-butadiene)Cl (and the 14 electron complexes Cp M(η 3 -1-methallyl)-Cl 2 ) by comproportionation with Cp MCl 3 [7].…”

Section: Synthesis and Derivatizationmentioning

confidence: 99%

“…The compounds Cp M(diene)Cl can readily be derivatized by substitution of the remaining chloride ligand to form Cp M(diene)R with R = alkyl, aryl, η 3 -allyl, η 2 -BH 4 [7,8]. IR and NMR spectroscopic data indicate the presence of "agostic" [13] CH · · · M interactions in the 14 electron alkyl complexes, emphasizing the electron-deficient nature of these compounds [7].…”

Section: Synthesis and Derivatizationmentioning

confidence: 99%

“…IR and NMR spectroscopic data indicate the presence of "agostic" [13] CH · · · M interactions in the 14 electron alkyl complexes, emphasizing the electron-deficient nature of these compounds [7]. Cp M(diene)Cl can form 16 electron adducts Cp M(diene)Cl · L with a variety of Lewis bases, such as trialkylphosphines, trialkylphosphites, pyridines, ketones, nitriles and THF [7].…”

Section: Synthesis and Derivatizationmentioning

confidence: 99%

“…Although several electronically unsaturated early transition metal diene complexes are known, such as the 16 electron species (diene) 2 M(dmpe) (M = Ti, Zr, Hf) [3], (C 8 H 8 )M(diene) (M = Ti, Zr, Hf) [4], CpV(diene)(PR 3 ) [5] and (C 5 Me 5 )Ta(diene)Cl 2 [6], very little has been reported about their reactivity. Studies on the unsaturated 14 electron complexes Cp M(diene)X (M = Ti [7], Zr, Hf [7,8]; X = Cl, alkyl, aryl; Cp = η 5 -C 5 Me 5 ) indicate that electronic and steric unsaturation can cause significant changes in the reactivity and reaction selectivity of the diene ligand.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Properties of electron deficient 1,3-diene complexes of the group 4A metals

Hessen

Teuben

1988

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

Section: Synthesis and Derivatizationmentioning

confidence: 99%

Section: Synthesis and Derivatizationmentioning

confidence: 99%

Section: Synthesis and Derivatizationmentioning

confidence: 99%

Section: Synthesis and Derivatizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Properties of electron deficient 1,3-diene complexes of the group 4A metals

Hessen

Teuben

1988

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

Titanium: Organometallic Chemistry

Mintz

2005

Encyclopedia of Inorganic Chemistry

View full text Add to dashboard Cite

The majority of titanium organometallic chemistry involves complexes in which the titanium is in its highest oxidation state (+4) with cyclopentadienyl derivatives as ancillary ligands. However, considerable chemistry has also been developed for complexes with titanium in the +3 and +2 oxidation state, with lesser amounts of chemistry developed for titanium in lower oxidation states (+1, 0). Since the early 1980s, chemists have placed considerable emphasis on the fine‐tuning of the structure and reactivity of titanium organometallic complexes. Particular emphasis has been devoted to tailoring the structure and reactivity of bis(cyclopentadienyl)titanium derivatives by incorporating electron‐donating, electron‐withdrawing, sterically demanding, or chiral substituents on the cyclopentadienyl ring. Considerable effort has gone into preparing ansa‐metallocenes with a wide variety of bridging groups and substituents to fine‐tune the reactivity catalysts prepared from them. In a similar manner, considerable effort has gone into the development of constrained geometry complexes. Several types of chiral substituted cyclopentadienyl, annulated cyclopentadienyl, ansa ‐metallocenes, and constrained geometry complexes have been prepared and applied to olefin polymerization and organic synthesis. Additional efforts at modifying the structure and reactivity by focusing on varying the oxidation state or coordination geometry at the titanium center have expanded over the past decade.

show abstract